I've seen Zuk's in a mud hole or in the sand bumping it off the rev limiter (6500 rpm's) for what seemed like minutes on end, over and over again.
When I'm in the same I will run it up to close to the limiter just before hitting the hills.
Highway I can run 70mph |removethispart|@ 4300 rpm's. I have 155,000 miles on my engine and it still runs great!