The Super Street car I change it every 30ish passes. Always looks great but the way I see it oil is cheap and it might help me see something going on before it gets bad. On the Hot Street car with the 99 hemi we have been known to change it twice in a weekend. Occasionally if we think we need that extra .02 or .03 we will throw in the thin stuff, but thin I mean 0W5. Usually the car runs a little thicker oil in it. But it is a heads up all motor deal so ya gotta do what ya gotta do.