Last night I was running fifth in a 27-lap race at Oscher B when I got a "fuel low, pit in" warning on lap 24. Grrr! I've noticed that this 3-lap discrepancy exists when doing a twelve-lap stint on this track, too. Has anyone else experienced it? Can it be attributable to the fact that I'm driving a non-stock car (Lotus Elise "Cup" mod, six gears)?
Finally does anyone know why Oscher B is not listed on GTR2Rank?
I had that happen to me during a race at Laguna, I did a 12 lap race with fuel for 14 laps, and ran out of fuel, in the lead, exiting the final turn heading for the flag. And since the front straight is up hill, I didn't make it to the line.
Your best bet is to check your own fuel mileage on any track during practice. I have found that the estimates are sometimes off, especially with add-on tracks.
I think I read somewhere that if you do a practice session (from the main menu, not during a race practice) and let the computer run some laps it will adjust the estimates, but I'm not completely sure.