Yah, US models do have the darn 156 mph speed limiter. The European models don't and the owner's manual says they top out at 186 mph.
Why is it that fast? Very low drag numbers in the Avant model and 350 HP.
Yah, its got ZZZWOWJC tires good for that speed and more.
I've never had it up to more than 135 in my old age.
Regards,
Frank