When i try a race with AI cars, the AI cars are out of fuel within 2 laps. (ok, it is a 15 mile track with an average speed of 155mph.) Still i think that the cars should be able to run longer. How can i achieve this?
Check what the default fuel load is for the mod. Also make sure you have "time scaled failures" turned off.
Under [Waypoint] in the AIW file look for the line 'FuelUse=xxxxx.xxxxxx', this number determines the fuel use.