I was having a long race (50 mins) with the Formula Reiza's and my fuel was just about gone with 30 mins to go in the race so I pitted.The pitstop repaired some damage but did not refuel my car.
Unfortunately, F.Reiza is supposed to be a full replica of a 2011 model F1 car INCLUDING no refuelling, hence the bigger fuel capacity than the other car styles. Problem is, there's a glitch/bug/whatever that lets the AI cars refuel anyways. I hate that. Same thing goes with the Formula Classic.
I just wish Reiza had a quick fix for this, but I doubt it. It's just something we've lived with.
Luckily this is offset by the AI never pitting. So he can just fill up the car for the whole race and he should be fine.
Minis have had refuelling allowed the whole time, or at least in ever since I got the full '12 game. Can't say the same for Classics, though. Might have to try that out....Or find an original download of Formula reiza, and use the hdv file from that car instead, which allows refuelling. I have not tried this with the F Reiza, but it certainly works with F Classics and Minis.