Solved

Amount of parts needed for repair

James Greer and I were a bit testing if we find anything that influence the amount of parts needed to repair the cars apart from tracks and lvl of Design without success.

Therefore I find it somewhat odd that another manager in my league, Craig Jones, needs so many parts to repair his cars that he can't fully repair both of them to the point of having one retiring due to part failure and this happening now in the second season in a row. He confirmed already his manufacturing is the same level as his design.

Now I know that at certain levels you do need more parts than you can produce due to running into the building lvl cap but usually it's to an amount that is manageable. So maybe a dev could look into his team ( https://igpmanager.com/app/d=profile&manager=46071 ) if things are in order, fix it if not or enlighten James and me what is causing that high of part requirements that we consistently overlooked do far.

@Craig: I hope you don't mind but I don't like mysteries I don't have any clue how to solve. ;-)

The first thing everyone should do is make sure they are getting the parts it's saying they should be getting each race.
It was noticed away back in early August that a few people where not getting the full amount of parts and a patch was ran to fix it.
People that transferred from the old version of the game that where on holidays or just not in leagues at the time the patch was ran might not of been affected and might still be getting less than they should be getting. It's the only reason I can think of, as to why someone cant maintain their cars.

I doubt it's that. As it came up last season he wrote he has level 8 design and manufacturing and he gets 8 parts. But he wrote he needed around 20 parts in some races. That's way more I needed even in Italy with both lvl 10 and 11 (both 14 parts total).

Yikes! He is level 12 and has level 8 design and manufacturing, sounds like the probable reason. 8 days of building up manufacturing will fix that.

That was last season as level 11, I don't think it's still as low as that and in my case leveling did nothing to my part needs, only getting the design up was causing a change. Even if it would be that he would need the same parts as me, as we are the same level, and not something between 50 and 100% more despite having a less leveled up design.