Solved

more fuel = more wear ?

hello there , new to game. 
couldn't find any info about it.
obviously more fuel make me slower but let's say , if i wanted to stretch my first stint, can i over fuel my car pre-race without worrying about ''game changer level'' more wear .

In my opinion, you can overfuel, but no more than 50 ltrs, after that your cars become real slow.

Depending on race lenght and track, 40 might be too much, already.