I would suggest a change to how the engine distribution work (I'm not referring to the supplier system).
Rather than having the possibility to change your engine for every race, with the 20 (10 if one car league) engines given every 20 races, I would like to have a seasonal management of a certain number of engines.
For example, every team, at the start of the season, has like 7 engines for each driver (with the number that could be set directly by the league host at the beginning of the season) and has to manage the usage of each of them during the whole calendar. This could introduce different management aspects to the game, like for example, giving a meaning to the cooling research area. Some players would prefer using brand new engines for the first races to push immediately, but doing this they will suffer a bit more at the end of the season to those who used them wisely.
Let me know what do you think. Thanks for the attention!