Chris
You can run quick races with them to gain EXP. It doesn't matter if you win the race or not so you can run the same engine for several races but It costs quite a lot of car parts.
Poisson
Hi Petros.
From my knowledge, reserve drivers do not gain experience, neither do they age.
The criteria to gain experience (1 stat every 10 races) and to age (1 year old every 20 races) is that they "must" be participating in the race, only then it counts
It is 1 exp every 20 races I think (unless they changed it recently)
Hi Chris, I am fairly new to this game, however, from my experience I can confirm that drivers gain +1 experience stat every 10 league races.
I've read for quick races, this exp gain for drivers is reduced to half and as such they need to participate in 20 quick races to gain +1 exp.