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Community => Non-audio hobbies and interests => Cars and Bikes => Topic started by: Dan Banquer on 6 Feb 2007, 12:10 pm
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O.K. guys, I've got a few questions on cars that someone might be able to help me with.
1. Why does my car get poorer gas mileage in the winter?
2. My Mechanic says that now that we have 10% ethanol in the gas we no longer need to use dry gas.
Is this true?
Thanks in advance for your input;
d.b.
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Well, the dry gas thing is accurate. Dry gas is just alcohol, which works as a drying agent and binds moisture. So if your already have ethanol in the fuel, you don't need to add more.
As to the decrease in gas mileage :scratch:. I drive a diesel, so what do I know? I average 45mpg year round. But then idling will not warm up a diesel and most folks do warm up their gas engines.....more time idling means a decrease in mpg? That's just speculation, but the logic seems to work.
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Well I can see the logic of longer idling, but I have noted a decrease in highway mileage that does not appear to account for idling; Or so I think at the moment.
d.b.
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In my car, which has a turbo, I get better mileage in the winter (as compared to other seasons where the AC isn't used -- the worst mileage is always with the AC on). The more dense air helps the gas mileage, and certainly helps power. Perhaps it's the opposite with non-turbo cars?
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Yep; I certainly get less mileage with the AC on. I have observed about 10 miles to the gallon less with the AC on for long trips.
d.b.
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Several things actually.
1. All the lubricating fluids in the car are thicker and less slippery which leads to more friction until everything warms up.
2. When the engine is cold, the fuel/air mix and spark timing isn't optimum so it's less efficient.
3. Cold air is denser, which means the engine needs a smaller volume of it to provide a given power. Therefore the throttle valve will be open less than usual at any given cruising speed, this means more pumping losses for the engine since it now works harder to suck in air.
4. The locking torque convertor in an automatic transmission may not lock up until it's warms up sufficiently. This leads to the engine reving higher and suffering more frictional and pumping losses which kills efficiency.
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2. When the engine is cold, the fuel/air mix and spark timing isn't optimum so it's less efficient.
3. Cold air is denser, which means the engine needs a smaller volume of it to provide a given power. Therefore the throttle valve will be open less than usual at any given cruising speed, this means more pumping losses for the engine since it now works harder to suck in air.
This would be more applicable to carburated engines versus fuel injected. Yes, till the engine is warm the car will run in a slighlty "lean" condition so that the engine gets up to operating temperature sooner(for cleaner combustion, and therefore cleaner emissions). But after that the ECU will monitor O2 and adjust spark and fuel based on RPM and load to optimise the air/fuel ratio.
Technically, your car's engine will almost always make more power (therefore work less harder) when it's colder, due to air being denser. Therefore, more efficiant, and more fuel efficiant. The load (or drag) from ancillaries (heater, defroster, wipers) will place a load via the alternator on the engine. Basically the same as a human cycling on level pavement vs on an incline. You will dispense more energy to maintain your speed when cycling on an incline vs on a level terrain. Same goes for your engine.
Transmission slippage, tire slippage due to icy conditions, higher viscosity of cold fluids (engine oil, transmission oil) account for some increase, but it shouldn't equal or surpass the load from ancillaries.
You may have a faulty sensor that is malfunctioning, and not properly accounting for temperature, therefore making your car run at a poor air/fuel mixture during the cold.
Cheers
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Well this is getting interesting. I did have a main engine sensor replaced this summer that was connected to the manifold. The difference in overall performance was rather noticeable. However, it did not appear to make much difference in the mileage.
Thanks to all for their input,
d.b.
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Tire pressure?
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Dan what make/model/year vehicle do you have?
Have you seen any malfunction indicator warning lights/messages?
Good thinking about the air pressure. Suprised it took this long to see that.
I've got more questions but need to know what kind of beast we're talking about first.
Bob
p.s. By the way, I smell a Saab 9.3 owner here.
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Dan what make/model/year vehicle do you have?
Have you seen any malfunction indicator warning lights/messages?
Good thinking about the air pressure. Suprised it took this long to see that.
I've got more questions but need to know what kind of beast we're talking about first.
Bob
p.s. By the way, I smell a Saab 9.3 owner here.
I think your smelling something else Bob; I own a 1996 SW1 Saturn with a single overhead cam engine and a 5 speed manual transmission. It's got about 139,000 miles on it. No warning or idiot lights are coming on.
I will certainly check my tire pressure; and good call, check the obvious things first!
d.b.
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In my car, which has a turbo, I get better mileage in the winter (as compared to other seasons where the AC isn't used -- the worst mileage is always with the AC on). The more dense air helps the gas mileage, and certainly helps power. Perhaps it's the opposite with non-turbo cars?
my last two cars as well as my last two trucks got the same gas milage with the air conditioning on in the summer. Small engines are much more affected by loads than a modern V6 or V8. But, I've noticed that when driving on the highway in very hilly country the multi displacment feature on my new car will go back to the full displacment more than I'd like.
gary
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Petroleum fueled engines use heat as the primary motive force (explosions of fuel in the cylinders causing expansion) so it seems reasonable that until the engine warms up, some of the heat and therefore expansion is lost. The cold weather of the last few days has reminded me of how stiff the automatic transmission fluid gets (validating what was mentioned above).
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Several things actually.
1. All the lubricating fluids in the car are thicker and less slippery which leads to more friction until everything warms up.
2. When the engine is cold, the fuel/air mix and spark timing isn't optimum so it's less efficient.
3. Cold air is denser, which means the engine needs a smaller volume of it to provide a given power. Therefore the throttle valve will be open less than usual at any given cruising speed, this means more pumping losses for the engine since it now works harder to suck in air.
4. The locking torque convertor in an automatic transmission may not lock up until it's warms up sufficiently. This leads to the engine reving higher and suffering more frictional and pumping losses which kills efficiency.
1** once the engine has circulated the oil for three or four minutes (most of the manufacturers are specing 5w-30) the oil is right where it should be. If you happen to be using synthetics; there is no real difference between cold oil and hot oil.
2**that would be true in an older car built in the seventies or sixties. But all the newer ones sense the ambiant temp, as well as engine temp, and adjust from there. You can't change it as it's in the computor that runs the engine and fuel delivery system.
3**virtually all fuel injection systems have a gas return line back to the tank or fuel delivery line. You will never use anymore gas than needed because the CPU will not allow it. Still if you happen to have a bad sensor the fuel injection system will automaticly go into a full fuel delivery. Might want to have a scan run on the sensors.
4**torque convertors are set to lock up at speed above forty mph, unless the speed sensor is out of wack. It's pretty much a mechanical thing after that.
gary
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Petroleum fueled engines use heat as the primary motive force (explosions of fuel in the cylinders causing expansion) so it seems reasonable that until the engine warms up, some of the heat and therefore expansion is lost. The cold weather of the last few days has reminded me of how stiff the automatic transmission fluid gets (validating what was mentioned above).
automatic transmission fluid is a synthetic , and is not bothered all that much with the ambient temp outside. What you maybe encountering is the temp of the valve body causing the spools inside tobe a little sluggish. There are only three manufacturers that have that part figured out. All are domestic manufacturers. Rest are still using technology from the sixties. With the advent of solenoid controlled valve bodies this is even more critical. To get around this some of the foreign folks are making the spools kinda loose in the basic body thus creating what is known as slippage in the oil supply.
gary
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1** once the engine has circulated the oil for three or four minutes (most of the manufacturers are specing 5w-30) the oil is right where it should be. If you happen to be using synthetics; there is no real difference between cold oil and hot oil.
Yes, the engine oil, which still leaves the transmission fluid, the differential oil, and the grease in the various bearings.
2**that would be true in an older car built in the seventies or sixties. But all the newer ones sense the ambiant temp, as well as engine temp, and adjust from there. You can't change it as it's in the computor that runs the engine and fuel delivery system.
Still true today. Try flooring the gas before the engine warms up to see how sluggish it is. When the engine is in warmup mode, power and efficiency go down the crapper, this is what it's supposed to do, as directed by the ECU for emmissions control reasons.
3**virtually all fuel injection systems have a gas return line back to the tank or fuel delivery line. You will never use anymore gas than needed because the CPU will not allow it. Still if you happen to have a bad sensor the fuel injection system will automaticly go into a full fuel delivery. Might want to have a scan run on the sensors.
I think we have a mis-understanding here. The engine is essentially an air pump, it takes X units of air to make Y units of power. When it's cold the air is denser, thus X units of air will fit into a smaller volume, so to make the same amount of power, for say cruising on the highway, a smaller volume of air is needed. To do that, the throttle valve is choked back, which results in more engine vacuum and pumping losses since you're now sucking air in through a smaller tube.
4**torque convertors are set to lock up at speed above forty mph, unless the speed sensor is out of wack. It's pretty much a mechanical thing after that.
In theory, and it also depends on the design of the darn thing. Some, like the one in my car don't lock up until the fluid is warm enough. Others have fuzzy logic which juggle speed, temperature, and a bunch of other parameters. Still others are strictly speed based.
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Dan, the Saab comment was directed at ctviggen (Viggen being a type of Saab).
Anything that would cause a 10mpg decrease in fuel economy that is monitored or controlled the PCM (Powertrain Control Module) {Also known by several other generic names: ECM ECU ect.."The brain" :roll:as some folks call it} SHOULD immediately turn on a MIL (Malfunction Indicator Light) in a U.S. vehicle built in 1996 or newer. All cars and light trucks built after that operate on a system called OBD II (On Board Diagnostics, second generation) All inputs and outputs of that module have a voltage range they operate in. If a sensor went 'bad' (full open or shorted circuit) would absolutely turn that light on. If one of these sensors (of which there are dozens of driveability/emission related sensors, solenoids, actuators, motors ect..) was 'bad' but stayed within it voltage 'window/spectrum', it may not turn the light on, because the PCM might be seeing that reading as plusible. (96 being an early OBD II vehicle, this system was in it's infancy and didn't "look at" as many things as a '07 vehicle does).
As a service department employee at a dealership, I'd be instantly sceptical of a vehicle that had that large of a drop in economy with no MIL.
That being said, if I were a technician I'd look at the following:
CTS/ETS (Coolant/Engine temperature sensors). A two wire sensor(s) located on the cylinder head. (Usually)
If the PCM was looking at a coolant temp of -225F (If I remember correctly, that was the default temp of most GM vehicles with an electrical 'open' in the CTS circuit) it would REALLY dump fuel in. Cold engines are less efficient than one at operating temperature, so the PCM is going to do everything in it's power to get it there. Cold air is more dense, meaning more fuel by nature, but within reason. NOT 10mpg. If the circuit was open, it WOULD turn the MIL on.
IAT (Intake Air Temperature) A Two wire sensor located in the air intake, between the air fiilter box and throttle body housing.
Once again, the PCM is looking at the temperature of the air coming into the engine.
MAF/MAP (Mass Air Flow/Manifold Absolute Pressure) 5-6 wire sensors (MAF is just after the IAT, MAF is usually remotely located {on the firewall?} with a vacuum hose running to the intake manifold.)
Can't remember which one or both a 96 Saturn has, but a MAF tells the PCM all about the density of air coming in the engine. MAF tell the PCM about the intake manifold level of vacuum. Both very important to fuel delivery/fuel management.
O2 (Oxygen Sensor) is a 4 wire sensor located in the exhaust manifold or slightly below, and a second one past the catalytic converter. VERY VERY important sensor that will cause a multitude of MIL's, driveability concerns as bad as needing a tow truck. This is the #1 sensor the PCM looks at for fuel delivery. It is the "God of all engine management sensors", no shit. They tell the PCM how much oxygen is in the exhaust stream (too much oxygen = too little fuel and visa versa). These operated on a rapidly floating/bouncing voltage (from .1 to 1.0 volt) and should cross the .5volt threshold many times a second back and forth (rich - lean - rich - lean) get it? If the sensor is slow/groggy, or is lingering on the end of the spectrum that tells the PCM, "HEY, I've got too much oxygen in here,--turn up the fuel!!", then you'd have crappy mpg. got it?
Those are some of the most common sensors I saw with GM vehicle (when I was working on them). There is many others that could be the culprit, but those are the one's I'd check first.
I've seen many bizzare things over the years that could create your symptoms that would NOT turn on the MIL.
Mice building a nest in your air filter box (choking the air).
Brakes dragging. Happens a lot in the winter time. Folks use the parking brake in sub freezing temps, the cable is frozen in the engaged position even though the brake handle/pedal is released. Causes the rear brakes to drag. Given enough time and speed, it would get the brakes hot enough to start causing damage. Do this: Park on a hill, nose down. Put transmission in neutral, slowly let off brake. If car wants to roll immediately, the brake isn't the problem. Got it? This condition is worsened by heat. So driving the car for awhile THEN do the test. (locking brakes = friction = heat = expansion of brake components = brakes apply harder = more friction = heat = more expansion...........)
My fingers are getting tired of typing, damn!
Have the car checked if your uncomfortable. Most libraries have service manuals if you want. But remember your digging in the EPA's back yard here, not real easy stuff... You could take it to a shop, but expect to pay about an hour diagnosis for the guy/shops time. They may not find anything after all that. Cheap solution, if your state/location has a manditory emission testing facility, have it checked. It's cheaper than a shop. If you fail the test some testing facilities will give the OBD DTC (Diagnostic Trouble Code) that was in your car. THEN you can follow down the path of that particular flow chart for that sensor.
Or, now that I think about it, "Auto Zone" (I assume you have those?) will check your codes for free.
Does that help at all? My fingers need a rest.
Bob
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Dan what make/model/year vehicle do you have?
Have you seen any malfunction indicator warning lights/messages?
Good thinking about the air pressure. Suprised it took this long to see that.
I've got more questions but need to know what kind of beast we're talking about first.
Bob
p.s. By the way, I smell a Saab 9.3 owner here.
I do have a 9-3 Viggen. It's a fun car. And useful to boot. (I chose my moniker not because I'm a car guy -- I'm not -- but because no one has this name anywhere.)
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Hi Bob;
Thank you very much for your rather extensive reply. I will study your response further and talk to my mechanic. BTW: The 10 miles per gallon reduction appears to be due to airconditioning only. Without the AC I will get close to 40 miles per gallon on the highway for long trips. I sincerely hope you were not confused by that.
Thanks again for taking the time and wear and tear on your fingers;
I owe you;
d.b.
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Hey guys, though I'd comment on a few things I've seen:
Dan does not have an automatic, so he does't have a valve body.
I don't believe Saturns EVER had a throttle valve.
He doesn't have a torque converter.
Transmission and differential fluid are the same fluid (same case housing).
This talk about fluid vicosity, jeez man, He'd have to have 90W in every fluid to make that much of a difference.
Dan, DON'T floor the gas of a cold engine. EVER. NEVER!!! :nono: No reason to. Where you live, that oil gets very thick and won't be lubricating the valvetrain components immediately. DON'T DO THAT!
Of course it's going to be sluggish on a cold start up.
Bob
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I do have a 9-3 Viggen. It's a fun car. And useful to boot. (I chose my moniker not because I'm a car guy -- I'm not -- but because no one has this name anywhere.)
Gotcha, just curious.
Bob - General Motors Guy!! aa
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1** once the engine has circulated the oil for three or four minutes (most of the manufacturers are specing 5w-30) the oil is right where it should be. If you happen to be using synthetics; there is no real difference between cold oil and hot oil.
Yes, the engine oil, which still leaves the transmission fluid, the differential oil, and the grease in the various bearings.
2**that would be true in an older car built in the seventies or sixties. But all the newer ones sense the ambiant temp, as well as engine temp, and adjust from there. You can't change it as it's in the computor that runs the engine and fuel delivery system.
Still true today. Try flooring the gas before the engine warms up to see how sluggish it is. When the engine is in warmup mode, power and efficiency go down the crapper, this is what it's supposed to do, as directed by the ECU for emmissions control reasons.
3**virtually all fuel injection systems have a gas return line back to the tank or fuel delivery line. You will never use anymore gas than needed because the CPU will not allow it. Still if you happen to have a bad sensor the fuel injection system will automaticly go into a full fuel delivery. Might want to have a scan run on the sensors.
I think we have a mis-understanding here. The engine is essentially an air pump, it takes X units of air to make Y units of power. When it's cold the air is denser, thus X units of air will fit into a smaller volume, so to make the same amount of power, for say cruising on the highway, a smaller volume of air is needed. To do that, the throttle valve is choked back, which results in more engine vacuum and pumping losses since you're now sucking air in through a smaller tube.
4**torque convertors are set to lock up at speed above forty mph, unless the speed sensor is out of wack. It's pretty much a mechanical thing after that.
In theory, and it also depends on the design of the darn thing. Some, like the one in my car don't lock up until the fluid is warm enough. Others have fuzzy logic which juggle speed, temperature, and a bunch of other parameters. Still others are strictly speed based.
I worked for the company that invented the lockup convertor as well as the variable pitch convertor. We were doing solenoid controlled gear boxes back in the very early eighties (albeit somewhat crude by todays standards). We were the people that built the first four or five generations of CPU controlled automatic transmissions, and the latest generation of E-Prom controlled ones. Have seen them all at one time or another, and with the exception of valve body technology; very little has changed in the last forty years. It takes a lot more horsepower to drive an automatic transmission than most folks realize. All transmissions can be divided into two basic designs, and neither one is all that much better than the other except in high load conditions. There is a third design looming that will make all these obsolite. It's projected to only use about 25% of the power, and it's the future (sorry Mercedes). It maynot use a torque convertor, but of course it can if needed. Cannot go much further into it, but it's on the test stands right now. There's also a type of automatic transmission that has a built in electric motor (think G.M. & Chrysler here) that make it's debut this coming fall in SUV's.
It's big and somewhat heavy, but still better than what they are using now. The Fed is really pushing the last one.
gary
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Gary, if you're responsible for some of the engineering ideas out there, I've got some technicians that want to have a chat with you (in a dark alley) (http://www.hometheatershack.com/forums/images/smilies/paddle.gif) :o
HA HA, sorry, just kidding Gary. :lol:
Bob
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O.K. guys, I've got a few questions on cars that someone might be able to help me with.
1. Why does my car get poorer gas mileage in the winter?
Fuels ability to atomize is directly porportionate to its ability to combust or convert to heat.
High efficiency designs run at a higher operating temperature allowing the maximum amount of fuel to vaporize before reaching the combustion process.
When intake tract and the ambient air temperature is low it takes more fuel to achieve this level of vaporized fuel, hence a richer mixture and poorer fuel economy. Direct injection is the closest thing we have for mitigating the cold weather scenario, but it also take fuel to heat the motor to a desired temp, this comes right out of the fuel mixture. Ideally your motor wants to be tempX and it takes fuel to creat that heat.
MTBE was used in winter fuel formulations to assist in having fuel vaporize.
Alcohol doesn't do the job MTBE did.
I could get more specific but had an ot shift last night and my brain feels like mush, maybe I'll invite some fuel guru friends to participate in this thread if y'all would be so inclined. I used to blend racing fuel and hang out with some very gifted fuel guys who brought me out of the dark ages on this topic.
I hope I didn't thoroughly step on my dick here, 3 hrs of sleep messes with my fuel functions.
Bill
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"I hope I didn't thoroughly step on my dick here, 3 hrs of sleep messes with my fuel functions."
If you can step on that then you are wasting your time in this forum! :lol:
Bring on the fuel guys; I have much to learn.
d.b.
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MTBE was used A) to prevent knocking and B) it is an oxygenate in other words it increases the oxtane of the fuel. This helps create a cleaner burn. Ethanol will not do these things. It will reduce the energy conatined in the fuel thus decreasing you mileage. Ethanol will remove water from your fuel becaue of its nonpolar structure. This is one of its HUGE downsides as a fuel because it cannot be shipped via pipeline. 2-Butanol is a much better fuel because A) it has one more bond so more energy B) it is less polar so it will not pick up water.
P.S. My mileage drops around 10% in the winter but that is because of the winter treated D2. My TDI still gets 45mpg so I am not complaining.
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Sorry guys if I'm a bit sceptical on using fuel blends as the reason for Dans decrease in economy. Working in the repair industry for the past couple decades, I'd be seeing hoards of people banging down my door if they noticed a 10mpg drop in efficiency. And that number is from a pretty fuel efficient vehicle, if it was the fuels fault, what would the Suburban, Excursion, Hummer owners be claiming for their mpg rating? :o
Besides, I believe the EPA would intervene if this happened to too many people.
By the way, I am the owner of a full size GM truck (5.3l) who's economy doesn't change by season.
Bob
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most people barely know where to put the gas never mind what mpg they are getting...
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Very true. :roll: Or they judge the mpg based on the useless trip computer :duh:
Bob
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Very true. :roll: Or they judge the mpg based on the useless trip computer :duh:
Bob
I agree...Sorta. I had a Lincoln Towncar, and A Cadillac Deville. I checked actual MPG compared the trip computer, and the computer almost always indicated better fuel economy, than reality.
I've had an Acura for 8 months, and the few times I did the compare, it seemed to be right on.
Alan
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Correct Alan, from what I've seen, they are either right, or indicate 'better' than actual economy. Hard to get some customers to realise that. Some aren't smart enough to use a calculator to check it for themselves.
So DAN, how's the Saturn coming along? Enquiring minds need to know!
Bob
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Well Bob;
The first thing I'm gonna do this weekend is check the air pressure in the tires. I'm waiting for the weekend because it is supposed to be warm enough so that I won't freeze my old fingers off doing it! The Saturn is doing fine so far, I am letting it warm up less, and when I start to drive I start off slowly so as not to strain it much. You can do that at 6:30 in the morning cause there ain't much traffic. The mileage appears to be improving. I also added about a half a tank of 89 Octane to the regular 87 Octane and this appears to help a bit, or I just could be fooling myself.
So Bob; am I fooling myself? or does this help a bit in the cold weather?
d.b.
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Sorry guys if I'm a bit sceptical on using fuel blends as the reason for Dans decrease in economy. Working in the repair industry for the past couple decades, I'd be seeing hoards of people banging down my door if they noticed a 10mpg drop in efficiency. And that number is from a pretty fuel efficient vehicle, if it was the fuels fault, what would the Suburban, Excursion, Hummer owners be claiming for their mpg rating? :o
Actually a fuel efficient vehicle would see a much higher MPG drop than a gas guzzler. Let's use a vehicle switching from regular gas to E85 as a worst case scenario, E85 having roughly 70-75% the energy content of gasoline per gallon. Car 1 is say, a Honda Civic getting about 50mpg, it'll take a 25% mileage hit on E85 dropping the fuel mileage to ~37mpg, a 13mpg hit. Car 2's a Hummer, about 10mpg on regular unleaded, on E85 it'll drop to about 7.5mph, that's only 2.5mpg lower.
In short, fuel efficient vehicles will see a much larger fluctuation in mpg numbers than gas guzzlers, but percentage-wise I'd bet it's pretty close. Which is why many countries use litres/100km instead of miles/gallon to measure fuel consumption.
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I also added about a half a tank of 89 Octane to the regular 87 Octane and this appears to help a bit, or I just could be fooling myself.
So Bob; am I fooling myself? or does this help a bit in the cold weather?
Dan -I wouldn't think it would make enough of a difference in your car to "save money". Your fuel delivery system is adaptive, so it would run a little more efficiently (better combustion process). But to justify the price per gallon, your not really gaining much.
Just out of curiosity, when was the last time the injectors/valve train cleaned of carbon deposists?
Keep us posted Dan!
aerius - I agree with what you just said. However, I wasn't refering to such a drastic change in blends. I was mainly talking about what changes the petrolium companies make from brand to brand, season to season, additive packages ect...
E85 is a marketing financial joke in my opinion. (I'll get blasted by someone for that one.)
Bob
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Gary, if you're responsible for some of the engineering ideas out there, I've got some technicians that want to have a chat with you (in a dark alley) (http://www.hometheatershack.com/forums/images/smilies/paddle.gif) :o
HA HA, sorry, just kidding Gary. :lol:
Bob
actually I retired in December with the golden handshake (if you know what I mean). The folks I worked for know more about hybrid drives than all the rest of the automotive world put together (not bragging as this is a well known fact). We've been doing fuel cells for five years, as well as hybrid electric drives. We also get the task of undoing miss engineering from other divisions, and there's plenty to go around.
Right now we can build you a mid sized Saturn that will get 80mpg with zero emissions (this is a fully loaded automatic transmission car), doubt any of here could afford one (about a million dollars a piece right now). That same car stripped down and with a manual transmission got 108 mpg, and was much faster than a gas engined car.
But the hold up right now is Eccotec and Baldwin Fluid Power's hydrogen fuel cells. Technology is really expensive these days, and moving so fast it's hard to keep up.
Right now the Fed is really pushing us for mass transit development. If you keep your eyes open you'll see are units all over the place in the bigger cities (N.Y.C. and L.A. for example). Yet these are nothing more than a stop gap measure, but get almost triple the gas milage. From what I saw the next big push will come in Class A RV's and medium duty trucks (think school buses) in a hybrid electric drive units. This technology is just way too expensive for automobiles right now, but it's just around the corner.
We messed with everything from gas turbine powered semis to four wheel drive electric cars thru the years. Some of it's a bust, and some of it's on the road right now.
gary
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Sorry guys if I'm a bit sceptical on using fuel blends as the reason for Dans decrease in economy. Working in the repair industry for the past couple decades, I'd be seeing hoards of people banging down my door if they noticed a 10mpg drop in efficiency. And that number is from a pretty fuel efficient vehicle, if it was the fuels fault, what would the Suburban, Excursion, Hummer owners be claiming for their mpg rating? :o
Besides, I believe the EPA would intervene if this happened to too many people.
By the way, I am the owner of a full size GM truck (5.3l) who's economy doesn't change by season.
Bob
I get 19 mpg out of my 5.3 in 2 wheel drive or 4 wheel drive on the highway. The H2 is nothing but a 1 ton Tahoe chassis with a box put ontop of it. Doubt they get 16 mpg. The Excursions are even worse. There is a couple new deisels being developed that are getting in the mid twenties, and are maybe 18 months away. That plus a certain new six (or even seven speed) automatic will make a huge difference. But you wont see them in the H2 hummer anytime soon.
gary
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Gary - you sound like you'd be a cool guy to sit down with a beverage and chat with.
Neat information there. As a service department employee, hybrids, electrics all that stuff scares the hell out of me. I'm glad I'm not the guy turning the wrench anymore. Anything "Non-Conventional" is just a pain in the ass to diagnose/service. Not enough training in the industry for the new radial stuff. And I mean radical stuff by "our" standards. Some of these guys in the shop have been working on cars since before cassette decks were standard. You think THEY are going to be able to adapt to a car driven by an electric motor, or hydrogen?
But the 'techie' in me, loves new technology. Like GM's new skateboard / Hy-Wire chassis. That things cool. aa
Even the GM "Volt" is pretty cool (Hope it works!)
Bob
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Opps, I was typing while you posted.
What 5.3 are you driving that your getting 19?! :o
(Modded H2, was I reading that right??)
Bob
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I also added about a half a tank of 89 Octane to the regular 87 Octane and this appears to help a bit, or I just could be fooling myself.
So Bob; am I fooling myself? or does this help a bit in the cold weather?
Dan -I wouldn't think it would make enough of a difference in your car to "save money". Your fuel delivery system is adaptive, so it would run a little more efficiently (better combustion process). But to justify the price per gallon, your not really gaining much.
Just out of curiosity, when was the last time the injectors/valve train cleaned of carbon deposits?
Keep us posted Dan!
Bob
Hi Bob;
I don't think I have ever had the injectors or valves pulled out and manually cleaned. I have used some fuel additives in the past that claimed that they would clean the carbon deposits but I am rather skeptical as it appeared that there was no increase in performance. My mechanic has told me flat out that these additives don't do diddly squat as there are plenty of additives in the fuel to take care of this.
What's your take on this?
d.b.
P.S. I only use the 89 Octane when it's very cold, (single digit temps) seems to help a bit when starting the car, or is this my imagination? The car does seem to run a bit smoother in the cold with a touch higher Octane mix.
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I don't think I have ever had the injectors or valves pulled out and manually cleaned.
No, not a physical removal of the parts, just a chemical cleaning.
I have used some fuel additives in the past that claimed that they would clean the carbon deposits but I am rather skeptical as it appeared that there was no increase in performance. My mechanic has told me flat out that these additives don't do diddly squat as there are plenty of additives in the fuel to take care of this.
Two products exist that I would put in MY fuel tank. One is only available only to industry, the other is "Chevron - Techron". A little expensive by "in the tank cleaners" standards, but it works.
I only use the 89 Octane when it's very cold, (single digit temps) seems to help a bit when starting the car, or is this my imagination? The car does seem to run a bit smoother in the cold with a touch higher Octane mix.
Definitely Plausible, sure. I'd buy that.
(We had a car in the shop this week with a very bad cold start problem. It would cough, sputter and die, repeatedly. It is 6 years old with 80K. Once it was up to operating temp it ran great. No warning lights seen, no codes in system.
We cleaned the injectors, now it fires up just like a new car.)
Just a point to ponder.........
Bob
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Gary - you sound like you'd be a cool guy to sit down with a beverage and chat with.
Neat information there. As a service department employee, hybrids, electrics all that stuff scares the hell out of me. I'm glad I'm not the guy turning the wrench anymore. Anything "Non-Conventional" is just a pain in the ass to diagnose/service. Not enough training in the industry for the new radial stuff. And I mean radical stuff by "our" standards. Some of these guys in the shop have been working on cars since before cassette decks were standard. You think THEY are going to be able to adapt to a car driven by an electric motor, or hydrogen?
But the 'techie' in me, loves new technology. Like GM's new skateboard / Hy-Wire chassis. That things cool. aa
Even the GM "Volt" is pretty cool (Hope it works!)
Bob
Right now all the money's being spent on hybrid electric drives, but there's still a lot of developmental work using hydrogen fuel cells. We're ready for fuel cells, but the actuall manufacturers are not. We've done a lot of work lately on hybrid / electric drive trains, and natural gas fueled deisels. We've got several in use right now, keep in mind this is a learning curve here. The engines are rather small for the aplication, and right now Cummins is the only one that's worth buying. But there's still at least one more new generation of deisels coming out. They'll be much quieter, and will not have the normal foul smell that is associated with them. Watch Honda and Chrysler this fall. Toyota like Ford wants the Cummins six cylinder deisel, but they can't buy it. But they can develope another engine for the same application, but not the one Dodge uses. Maybe built at Walesborough Indiana, but then again that motor maybe installed in the new Chrysler 300. All we know is somebody's going to get into the deisel market in a big way.
Anybody here ready for the 600 hp. super Corvette yet? Rumor has a $120K price tag.
gary
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I'm surprised Mecedes allows Chrysler to continue using the Cummins. Since Benz has thier own diesel, you know.
Regarding the super Vette....Yea, I'm ready. Reasons like that are why I regret leaving the Chevy dealership. The testdrives were fun..... aa :o
Gotta 'break 'em in right....know what I mean 8)
Check out the Saab concept. VERY very cool, but would never make it in the real world.
Bob
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I'm surprised Mecedes allows Chrysler to continue using the Cummins. Since Benz has thier own diesel, you know.
Regarding the super Vette....Yea, I'm ready. Reasons like that are why I regret leaving the Chevy dealership. The testdrives were fun..... aa :o
Gotta 'break 'em in right....know what I mean 8)
Check out the Saab concept. VERY very cool, but would never make it in the real world.
Bob
The Mercedes deisel is junk compared to the Cummins. Besides, it would look to me like Mercedes would use the Detroit Deisle engines in the U.S. market (they own that company). We had them (and probably still do) on the test stands for quite awhile, and the Cummins out performed them in everyway. The Cats are good, and make lots of power (I mean lots of power). But under heavy load conditions the Cummins is still better, and with the new emissions spec the Cat's not gonna make it. The Duramax has finally got all it's teething problems straitened out, so it seems. Those motors used blow up in less than three weeks on the dyno for the first two years they made them. But the redesigned a lot of stuff on them. The Navastar has had a ton of electrical issues, and we are hearing that Ford is engine shopping if they don't get all
the problems fixed. Dodge had an issue with the timing gears for awhile on the new motor, but seems to be resolved (we never did see this problem at work). But with all these problems the American deisel technology is a light year ahead of anything coming out of Europe, and maybe two light years ahead of anything out of Asia. And those twenty odd test cells don't tell lies. They just send the engines back out on skids ready for the junk pile.
gary
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"Teething problems", that's a good description of what they (GM/Isuzu) was going through for awhile.
I had only seen one Duramax replaced (it was in a '02?? maybe) But that guy owned a construction company, and had a horrible PM record with all of his equipment. All of the problems with the Duramax appeared to be related to fuel in one way or another. Especially lack of fuel filter replacement, they seemed to be a little too sensitive in that respect. But good engine/drivetrains from what I found.
When you say American diesels are ahead of Asians, which camp are you including the Duramax?
Surprised to hear the Cummins is that good. I have no dealings with them, just not a big fan of those smoke rollin' noise makers. Kind of a uninformed/biased opinion of mine there to be totally honest.
Bob
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But with all these problems the American deisel technology is a light year ahead of anything coming out of Europe, and maybe two light years ahead of anything out of Asia.
gary
When you say "anything" coming out of Europe, are you including whatever diesel it is powering this Citroen 7 passenger van (weighing 3564 lb and seating 7) to 119 mph with a zero to 60 of 13 sec., and delivering 49.6 mpg in the process?
http://www.honestjohn.co.uk/road_tests/index.htm?id=256
(scroll to end of test)
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But with all these problems the American deisel technology is a light year ahead of anything coming out of Europe, and maybe two light years ahead of anything out of Asia.
gary
When you say "anything" coming out of Europe, are you including whatever diesel it is powering this Citroen 7 passenger van ...
Is the diesel you reference "coming out" of Europe, or is it staying put?
I haven't seen a Citroen in years.
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It's probably staying put. Don't see them in Canada, either, although I can't speak for Quebec.
Citroen seem not to be interested in jumping through the hoops necessary to export to North America
I see in the Wikipedia entry:
http://en.wikipedia.org/wiki/Turbocharged_Direct_Injection
... that Audi was the first with TDIs (turbo direct injection) in 1989.
My limited understanding of the matter as to why we are not seeing these engines in N America is that the fuel is not quite right for them, or at least that was true until recently.
With Europe's fuel prices, it's not surprising to see this developed there first. From what I read, many of these cars when running these newer-tech diesels exhibit few if any of the characteristics we associate with diesels - dificult starting, noisy idle and running and smelly exhaust.
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"Teething problems", that's a good description of what they (GM/Isuzu) was going through for awhile.
I had only seen one Duramax replaced (it was in a '02?? maybe) But that guy owned a construction company, and had a horrible PM record with all of his equipment. All of the problems with the Duramax appeared to be related to fuel in one way or another. Especially lack of fuel filter replacement, they seemed to be a little too sensitive in that respect. But good engine/drivetrains from what I found.
When you say American diesels are ahead of Asians, which camp are you including the Duramax?
Surprised to hear the Cummins is that good. I have no dealings with them, just not a big fan of those smoke rollin' noise makers. Kind of a uninformed/biased opinion of mine there to be totally honest.
Bob
if you have a Duramax made prior to 2004 it probably has a cracked cylinder head (or is heading that way). They also had a major problem with the head bolts stretching, and even ripping the threads out of the block. The engines we blew up were all massive block failures (we blew up several dozen). The last one actually split right thru the middle. Japs have never made a good deisel engine, and everybody but the bean counters at G.M. knows this. As for catastropic failures in the field, I've seen three let go on the highway. But not in the last two years, so things are getting better there.
Toyota is going to do a deisel, and it will be interesting to see how they go about it.
Deisels tend to eat torque converters like a kid eating a Hersey bar. Are they planning on enfringing on someone's patents? I suspect they'll try to use the Asian transmission out of Japan like Dodge is going to do. This is nothing but a 500 series Allison automatic with a parking brake installed (DOT mandated rule), but knowing Dodge they have a total lock on that transmission's sales. All this will be interesting.
gary
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Hi Bob;
I checked the tire pressure this weekend and that's O.K. I also bought the Chevron/Techron injector cleaner for about $15.00 at the local auto parts store. At the end of this week when my gas tank is low I will add the injector cleaner and get back to you after a few weeks. I hope I get my fifteen bucks worth.
d.b.
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But with all these problems the American diesel technology is a light year ahead of anything coming out of Europe, and maybe two light years ahead of anything out of Asia.
gary
When you say "anything" coming out of Europe, are you including whatever diesel it is powering this Citroen 7 passenger van ...
Is the diesel you reference "coming out" of Europe, or is it staying put?
I haven't seen a Citroen in years.
actually was referring to the truck market as well as the RV market. Automobile diesels seem to be dead in Europe right now, but with two or three exceptions. Funny thing is the hot one over there is the Chrysler 300 powered by a Mercedes diesel. And you can't buy the same thing in a Mercedes. If the Europeans adopt the new emissions spec everybody over there will have to come up with completely new designs except for Mercedes automobile engines. Basically it's the CARB spec from California, and it's really tight. That's why Jeep dropped the diesel in the Liberty. The U.S. manufacturers seem to be the only ones making any headway in getting engine packages certified. Cummins is at the forefront, and is tooling up a new engine for cars (maybe Honda or Chrysler).
2007 / 2008 will be a very interesting development cycle in the work of diesel engines.
gary
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"Teething problems", that's a good description of what they (GM/Isuzu) was going through for awhile.
I had only seen one Duramax replaced (it was in a '02?? maybe) But that guy owned a construction company, and had a horrible PM record with all of his equipment. All of the problems with the Duramax appeared to be related to fuel in one way or another. Especially lack of fuel filter replacement, they seemed to be a little too sensitive in that respect. But good engine/drivetrains from what I found.
When you say American diesels are ahead of Asians, which camp are you including the Duramax?
Surprised to hear the Cummins is that good. I have no dealings with them, just not a big fan of those smoke rollin' noise makers. Kind of a uninformed/biased opinion of mine there to be totally honest.
Bob
like I said the Duramax had some severe teething problems, and was rushed into service at least a year too soon. It seems to be doing quite well right now, but how it will fare in the new emission fiasco I don't know. When they ship one to CA, I do know that it takes a 20% hit in power to meet the CARB specs. The Cummins is an old diesel company, and they seem to be the leader. I know we put 786,000 miles on one pulling a
trailer that had a 10,000lb cube of solid concrete on it with out any form of a failure. When we shiped it back to Cummins, and figured the motor was good for at least another 100K miles. It's hard to break one, but we did wear one out once on the dyno! The motor still ran well, but wasn't making any real power. This is the one motor we've never been able to tear up! Cats are great motors that make lots of power, but tend to eat lots of fuel. Can't really tear one of these up either. Eventually all this technology may well find it's way into the sedan we buy at the new car dealership, but of course in a much smaller package. Two companys right now are working day and night on 4.5 litre engines that will fit in half ton pickups and maybe a full sized car.
gary
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Dan, drive that car like you stole it!! Run the piss out of it. Blow all the nasties right out of the tailpipe.
(Can't find an appropriate smiley for that one!)
Gary, that one Duramax failure we had was abuse. The cylinder walls had the darkest blue spots I'd ever seen on a piece of metal. Darker than any brake rotor, flywheel, or clutch pressure plate I've ever seen. He "smoked it", plane and simple. The only consistant problems we saw were fuel related. The damn things needed two or three fuel filter added on. Rust and corrosion just packed behind the injectors. Nasty.
Bob
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I have driven a Duarmax and it is a nice rig... They definately need to be taken care of with maintenance regularely. I mean think about it, these things put out HUGE amounts of power, more than any even ten years ago would of ever bargained to see.
Cummins is the lead in power and what not there is just one thing that has bothered me... Dodge's tendency to use crappy transmissions and the bodies on their pickups have been really cheasy (not held together well) since the change to the pre-modern ones before our current style. I am not sure about the current transmissions, but the mid 90s stuff was awful.
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Dan, drive that car like you stole it!! Run the piss out of it. Blow all the nasties right out of the tailpipe.
(Can't find an appropriate smiley for that one!)
Gary, that one Duramax failure we had was abuse. The cylinder walls had the darkest blue spots I'd ever seen on a piece of metal. Darker than any brake rotor, flywheel, or clutch pressure plate I've ever seen. He "smoked it", plane and simple. The only consistant problems we saw were fuel related. The damn things needed two or three fuel filter added on. Rust and corrosion just packed behind the injectors. Nasty.
Bob
sounds to me like he had some antifreeze in the combustion chamber. I'm glad all worked out for him in the end. Nobody deserves a bad car or truck no matter whatkind it is. I looked at a 427 Chevy yesterday at my brother's shop, and the mains must have been .025" out of line!! Never saw one shift that much. Lucky thing for the owner is that it's going in an RV tow truck. Will be nothing but a low speed motor from now on, but it's going tobe a lot of cast iron coming out of that block in the line bore operation. Glad I'm not putting gas in it!
gary
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I have driven a Duarmax and it is a nice rig... They definately need to be taken care of with maintenance regularely. I mean think about it, these things put out HUGE amounts of power, more than any even ten years ago would of ever bargained to see.
Cummins is the lead in power and what not there is just one thing that has bothered me... Dodge's tendency to use crappy transmissions and the bodies on their pickups have been really cheasy (not held together well) since the change to the pre-modern ones before our current style. I am not sure about the current transmissions, but the mid 90s stuff was awful.
Diesels are really hard on torque converters. They'll eat the splines up in no time, and all that crap just flows back into the transmission. There is only one light duty transmission that will for sure hold up the a diesel (there's a lot more to this than just the torque converter by the way). There was another but they discontinued it for a newer product line, and it didn't conform to the DOT rules for 13,000 and lighter trucks.
There is a Jap gearbox thats called an Asian. It's nothing but an Allisson AT542 clone, and somehow they've added a parking brake. How they did it I don't know as the internal parking brake in a heavy duty unit is restricted if they use a mechanical paw.
Anyway from what I've heard is that Dodge will be either using this one or one from ZF designed for a medium duty truck. Either one will hold up just fine assuming they got the torque converter right. But keep one thing in mind here. The AT was never designed to take that kind of power, unless they've really beefed it up. Mercedes is buy LCT 2000 series transmissions like they're going out of style, and it's made to take that kind of power with out the slightest hitch.
Getting back to Dodge and the automatic transmission failures, a couple years ago they redesigned the torque converters and seem to be ahead of that problem. But new stuff is on the way. As for their bodies, I know lots of folks that have them without the slightest problems. I know a veterinarian that has one, and last I heard she had 736K on it. And she tows large horse trailers all the time. Myself I think the new ones are ugly!
But they are truly a work truck. We had a couple at work, and were astounded at how reliable they were. By the way you ought to drive one of them with the 1240 Ft. lb of torque motor!! I drove one once, as well as one with the 800 ft lb. motor. Still have no idea what anybody with any sanity needs with that kind of power.
gary
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Still have no idea what anybody with any sanity needs with that kind of power.
The guys that drive those trucks would probably say the same about our over-glorified "radios" and TV's! :lol:
Bob
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Still have no idea what anybody with any sanity needs with that kind of power.
The guys that drive those trucks would probably say the same about our over-glorified "radios" and TV's! :lol:
Bob
good thought! Mark (the guy with the 1240 ft. lb. Cummins) often has asked me about that. I just tell him that if he wants Hank Williams JR. done right, then he's got to move on up (he's a real Hank JR. fan)!!
gary
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Bob: I filled up last night and put the Chevron Techron fuel additive/cleaner in the tank. The countdown begins!
d.b.
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Ok Dan good.
Now, drive it hard - blow it out!! Drive it until the fuel level is as low as your comfortable (don't run out). Just don't run it down to a half tank and refill it. It'll dilute it too much.
Then fill up to full and remeasure your economy.
If you happen to have the local emission testing facility check your HC/CO/NOX's, don't do it while the cleaner is in the tank.
Bob
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Ok Dan good.
Now, drive it hard - blow it out!! Drive it until the fuel level is as low as your comfortable (don't run out). Just don't run it down to a half tank and refill it. It'll dilute it too much.
Then fill up to full and remeasure your economy.
If you happen to have the local emission testing facility check your HC/CO/NOX's, don't do it while the cleaner is in the tank.
Bob
I usually fill up at when I'm down to 1/4 tank, it must be the old habits of not letting the tank go low in winter for fear of freeze up. I guess that really should not be the case anymore with 10% ethanol?
d.b.
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You should be fine. Two dangers exist letting it get too low:
- Running out of fuel
- Sloshing the fuel around and making the fuel pump suck air. That's bad for it. The fuel is the pumps lubricant.
I'd run it to about 1/8 tank.
Bob
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Actually I kind of look at 10 percent ethanol in gasoline as "hamburger helper" for fuel. My mileage drops 10 percent in Minnesota winter when that farmer subsidy is always added. it is an insane additive inasmuch as it takes more than a gallon of gas or diesel to make a gallon of corn grain fuel. It works in Brazil where the source is sugar cane, but not in the USA from corn grain. See a recent issue of Scientific American for details.
Diesels? I had a couple of VW ones years ago, they shook all the accessory equipment on the engines apart - - starters, AC hoses, pumps, etc. Saved on fuel, paid thru the nose on repairs, and gutless wonders. Only fun was driving up Colorado mountain passes smogging everyone behind me with solid black stinking smoke screens while holding up the whole line of traffic. :)
I am still happy with my "friend of OPEC special" Audi S6. See you all at Audiokarma in Detroit end of March, driving there non-stop from Minn to share a display room with Salk Speakers assuming I have any equipment I can spare to display. Sales are beyond outstanding right now.
Regards,
Frank Van Alstine
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Diesels? I had a couple of VW ones years ago, they shook all the accessory equipment on the engines apart - - starters, AC hoses, pumps, etc. Saved on fuel, paid thru the nose on repairs, and gutless wonders. Only fun was driving up Colorado mountain passes smogging everyone behind me with solid black stinking smoke screens while holding up the whole line of traffic. :)
Regards,
Frank Van Alstine
So that was you!!
I always thought it was a little ironic that those Mercedes diesels, which really are quite nice to drive, make life so unpleasant for anyone within 400 feet of their back end. Same with diesel Jettas. I pull way back, or pass ASAP.
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Ok Dan good.
Now, drive it hard - blow it out!!
Drive it like you stole it, is my motto.
Oh yeah. Keep it shiny side up, is my other motto. :lol:
Cheers :green:
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Ok Dan good.
Now, drive it hard - blow it out!!
Drive it like you stole it, is my motto.
Oh yeah. Keep it shiny side up, is my other motto. :lol:
Cheers :green:
You want me to do that commuting back and forth on 128? God help me and every driver who comes in contact with me! :rotflmao:
d.b.
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Well It's been over a week and I have refueled. I did notice while the Chevron Techron fuel additive was in the tank some increased acceleration and less "coughing" as I would go down a hill without my foot on the pedal. I also noticed that my mileage remained at it's 30 miles per gallon, but that's a good thing as the weather last week really slowed up traffic for a few days so I wound up in stop and go traffic and very slow moving traffic.
I will report back next week if all is still looking good or not.
Thanks Bob;
d.b.
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Good deal Dan, keep us posted.
Bob
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You want me to do that commuting back and forth on 128? God help me and every driver who comes in contact with me!
Gotta live on the edge a little. :wink: C'mon, take a walk on the wild side, Dan. :lol:
Cheers
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You want me to do that commuting back and forth on 128? God help me and every driver who comes in contact with me!
Gotta live on the edge a little. :wink: C'mon, take a walk on the wild side, Dan.
Yea, come on Dan, just tell the arresting officer you were doing it in the interest of the environment. :lol:
Bob
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O.K. guys, I did get the tacometer up to 4,000 rpm a few times, but it's still pretty tough to chirp the tires with a 100 horsepower engine and Dunlop SP 40's. Besides, I'm 54 and by definition too old for this s__t
I'd swear you guys are bunch of overgrown juvenile delinquents. :lol:
d.b.
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You say that like it's a bad thing. :lol:
Cheers 8)
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I just filled up the car again and from what I am seeing I am getting about 33 miles per gallon for commuting. The Saturn is rated for 25 city and 38 highway, and I usually get about 30 mpg for commuting in the winter. So given the numbers I'd have to say the Chevron Techron fuel additive helped fuel efficiency also.
Thanks again Bob!
d.b.
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No problem Dan. I suck so much good audio information from these forums, I feel like I need to return the favor when and how I can.
Don't be shy about dumping another bottle in the tank Dan. The carbon that got knocked away isn't all of it, there is still some hanging on in your engine.
Bob