Why USA Q7's have a Top speed electronically limited at 130 mph and EU models are without the limitation?

I don't think US models have top speed limiter either, at least not until 140+ mph. I was on open stretch empty highway at 3 am coming home and went up to 140 mph. When I got home, I checked the Audi website to see the top speed of Q7, and it did say electronically limited at 130 mph though. By the way, it was Q7 3.6.

<There was absolutely no cars on highway except mine>

I'll say it's because it's a big heavy machine that can't stop all that quickly when going 150.

The Q7 and my A8 are supposedly limited at 135. The Q7 appears to be limited-- according to the manual. I have never driven over 120 -- just don't think I can handle that kind of speed. The A8 manual says limit at135 mph-- the engine with return automatically to "idle" until the vehical is stopped and shut of and on. I think the reason in the US is liablity. Thank your friendly lawyers -- V rated (typical) are 149 mph as the highest safe speed, so they are limited to some safe speed based on the average V and H speed rated tires.