fast as the z would do is 147 had it buried a few different times for ar least 20- 30 miles, between 2-3 in the morning when I would get off work, talk about getting home quick. Usually a 45 minute drive - doing 147 got home in at least 15 minutes. Ive also done this many nights in the rx- 7 which will hit the speed of 155. People ask me why I need racing harnesses for a n/a well now u know. Doing 150 for 20 -30 miles at a time is pretty intense.