I just had a quick look at his stream. He is a quicker* driver than me, but my race times short shifting in the 911 are quicker than his. A lot of those streamers assume they know the best strat/car combo and it becomes a self-reinforcing circle of ignorance. They all persisted in the BRZ at Suzuka when it was nowhere near META.
The likely candidates for competitive no stop racing at NGP are the 911 (the only one I've tried in-race), Jag, RCF and AMG. There could be others, but these are the ones I'd try first. To be honest, the fuel is less of an issue than the tyres by the end. The cars are very slippery on the last lap.