R2 can work for races at 3-5 laps, but for longer race you either have to play around with setups that ease the pressure on the tyres or using a R2 and upwards. But again, how realistic is that amount of laps? usually there is around 10+ min races, and that is often more than that amount of laps, and then the tyres are pretty much useless after 6+ minutes and then you have to drive around skidding the last 4 minutes which is a nightmare.