with the exception of neighborhoods and stuff like that, or the 25-35mph roads. i usually set the cruise at 84 on the interstate and do 10-14 over on all 45-55mph roads. i occasionally hit 160 or 165 on a close to empty interstate, but thats pretty rare. ran with a z06 the other day on the interstate to about 165, loads of fun. i think being lucky is part of it, but also, you have to be aware of your car. you have to be confident so that you aren't scared the whole time you are driving, but you still have to know that the beast could own you if it wanted to. i would never drive like that on worn out tires or tires that are not rated for it.