The F1 25 world car becoming slow at 1000 tech is a known bug, likely caused by a scaling issue where the game slows down high-tech cars in events. A common workaround is to dismantle your vehicle pa...
Ideas
This issue is PS5 as well, we play with 1 friend that have a PS5 and as soon he hit tech level 600 the car was slower and undrivable.
There is lots of variables you need to remember. Is he in higher tech races than his tech level, what bonuses and perks is he using, what quality parts is he using. We play with many PS players and no one seems to have the issue, only on pc. We've got guys who have gone from PC to PS or Xbox just to solve the problem. Lets not get ahead of ourselves and create an issue on other platforms when its not a definite problem.
Can you list what setup, parts, quality hes using and what tech level he is and what level events hes going in.
We have folk on PS and Xbox who are ridiculously fast and consistently setting mad laps deep into races, its always the PC ones left behind