just got to level 30 and I'm struggling with the 2 endurance races. Any help would be appreciated - Thanks in advance
Same strategy for the Porsche one. I dialed the Porsche back to N400 for 20% bonus (and less fuel usage).
I took a different approach; I didn't worry about saving fuel and just gunned them on RM tyres and pitted when the tyres were getting lairy, fuelling for the same amount of laps.
On the Gp.1 one, in the TS050 with 100% power, I think a set of Mediums were good for 20 mins. The leader was on a one stop strategy but put in some slow laps before his stop. I overtook him while he was in the pits and pulled out enough time that, after my second stop, I came out right behind the lead group of 2 or 3 cars, and had about 18 minutes left to pass them (which took a lap on my new rubber).
On the Porsche race, I think I had the power at 100% but possibly lightened the car slightly and stiffened the suspension up to stop it wallowing about on the S curves. I started on RH, but it started you off on less than a full tank of fuel, so I pitted after that was used (can't remember exactly, maybe 6 laps?) then stuck RMs on because it was quite lairy on RHs, and divided the remaining 24 laps into three stints of 8 (or something like that). At the start I could claw back a few secs per lap on the leader, but it got easier with RMs and by the end, I'd lapped most of the field and had a big lead.
I think the key is to not over-drive it. It's better to have consistently decent laps than get in some flyers and then lose time on the grass. Keep an eye on the red delta from the leader and work out how much you need per lap to catch them within the time. If you can't exceed that to give yourself time for extra pit stops - if they're running longer stints - and the occasional shonky lap, consider whether if would be worth getting softer tyres and adding an extra stop. RM should serve you well, though.
Edit to add: I also always fuel for a lap longer than I need, in case I do something stupid like miss the pit entrance! Better safe than sorry!