I practiced like hell this week. My wife was always complaining..... hehe
OK, with the GT2 that would mean 2 pits stops minimum.
100l for about 16 laps only.
With Hard slicks, I seem to get an lap times between 1.31 and 1.32
My personal best: 1.29.969 (yesterday) qualifying time.
Ferrari 360 GTC
Fuel usage is a lot lower = 29 laps for 100l
So 1 pit stop will be enough
Lap times are higher though. Still need to test a full tank ( or about 20 laps )
These are of course my personal findings. I hope I'm a little bit close to reality.