Quote Originally Posted by callard View Post
Grand AM ST and GT classes (sedan cars similar to IT - not prototypes) run two to three hour sprint races as the norm. No mandatory time for pit stops but usually with two drivers. They also run a 6-hour Enduro at the end of the season at VIR for those cars. Just sayin....
Chuck
Actually, they require a driver change. That means they require a pitstop. Of course none of the cars could run 2.5 hours on a single tank of fuel anyway. The cars fuel load is regulated so that no team/car has an advantage.

The 6 hour race was reduced to 4 hours this season as well, because of increasing expenses and falling car count.

So, some of this applies and some doesn't.