It is not the tires or even track conditions. The tires have been 16"-18" wide for years and the track conditions have always been dirt that either dries out or rubbers up. It is all the cockpit adjustable shocks, weight jackers and now "dri-bars".

Back 10-15 years ago it came down to who started with the best set-up and the driver who could carry a car to the end. This created separation and forced guys to search the race track for the best line that worked for their set-up.