I had my 2005 limited up to 151 mph. The top was down. No passenger. Some luggage. GPS confirmed on the top speed. The speedometer and the GPS have always shown the same speed.

The car pulled well all the way up. This was on a deserted highway in the dessert between California and Arizona. I wouldn't do it again because of all the laws that breaks. Speeding being the least of the tickets.

Afterward I got the best mileage of the trip from the next tank of gas. Must have cleaned out any soot deposits.