Used the R8 LMS (Audi Sport Team WRT) '15 and got gold
It wasn't my first try as I was trying out different strategies (and maybe rage quit because I crashed a few times).
The winning strategy was Hard tires for the first 3 laps on fuel mix 6 and then pit on the
END of lap 3 and put on softs and refuled to about 1.2 laps. (0.2 was in case of mistakes.
If you are good at saving fuel or actually knows how to play this game without crashing every 2 mins, you could probably do a no stop on hard in fuel mix 6 as gorlt says above.
My race time was 35:37 and finished with a 27 or so second gap to 2nd place. I also made plenty of mistakes with around 4 or 5 big spins, so it was pretty easy to get gold.
I used the setup shown in the following video, and my car was maxed (highest HP and lowest weight)
https://ru-clip.com/video/pQ1tYgT6N...ms-gr3-allround-setup-bop-leistungslevel.html
The video is in German and I need to to convert & round some of the units, but it should be fine. The car is a little unstable after throttle liftoff, so just feather it and make sure you don't brake and turn, or else you will crash a lot like I did in previous tries.
In general, my upgrading and car is probably overkill for this challenge, but I'm not very good at this game. I tried out the FT-1 VGT Gr.3, but I didn't like the handling so I switched back, but I guess that's personal preference.
Also note that I am on controller.