Undoubtedly, and all through this weekend's race, the subject of engine failure will arise. For good reason, to be sure. So, are engines (torerances, I suppose) built any different for 600 miles. If so, it would seem logical that a Charlotte/600 mile engine might be down a bit on HP. Or, if a 600 mile engine isn't any different, does it come down to the driver to be a bit less aggressive during the course of the race?