A few thoughts on this race:
1. If you do a pit stop and take 4 tires you will loose 1min and 10-15 seconds to the leaders (actual pit stop is much less but slowing down, going through the pits and getting going again cost you this much with these cars). So 70 seconds if the leaders continue on at the pace they are driving.
2. The race is 20-21 laps. Therefore you can average 3 seconds a lap slower with no pit stop and still be ahead by 10 seconds if you manage to finish the race without a pit stop.
3. The tire wear and damage model in R3E is a bit difficult to figure out so be careful. I have made every possible setup change to spare the inside left tire from wear and there is exactly 0 difference in wear over the same amount of laps. You can't adjust air pressure so that doesn't help.
4. Even stranger is the fact that you can be at 0-10% on a tire and still mange the same lap times as long as you never hit a curb or lock your brakes up. If for any reason you get a flat spot you can almost be assured of a flat tire within the next 5 laps. With high tire wear traction is a bit less but with careful driving you won't really see much drop off in lap time unless you make a mistake.
My conclusion is if you want to be in the top 4 or 5 you pretty much have to do it by not making a pit stop unless there are only two who manage to go the distance without a pitstop. If you have any lock up along the way you will most definitely have to make a pit stop unless you are very lucky. In the Nissan with avg lap time of 2:05.5 in an AI race I had two flats. When I did average lap times of 2:07 I had 38% tire wear left and no flats.
So drive carefully!!