Solved

Driver health

My drivers entered the race at 40% health and when the race was over their health were at 73%.
Is this what happens because I thought the drivers enter at the health they are at currnetly and not at 100% health.

Their health increased after the race?

Yup I was very tensed to think they might not finish the race with such low health but they did finish and had 73% health to my surprise. Considering the health loss which was 0.7 per lap and 0.9 in the lap after the pit with 2 pit stops and 42 laps, which I think it should be 29.8% health loss. I don't know how they were at 73% with both drivers entering at 40% health.

This is a known issue. It just hasn't had time to be fixed yet.

Oh its just a bug which occurs randomly?

So going on Nayan's calculations of health lost per lap, so long as we make aure our driver has at least that amount of health prior to the race (29.8%) then we can safely say that his driving will be unaffected and will end the race with a health boost to 73%?

I can confirm the exact same thing happened to me, start race 46% end race at 73% health . What I would like to know is does racing them at 40% health instead of 100% health have any effect on their performance?

I don't know, but regardless, it is a bug that will be fixed.

I just tested this and they race at 100% health at the start of the race, so it has no adverse affect upon their performance.

Drivers between 20-25% health start the race with 100% health. Lower than that start with roughly 75% health, take good advantage of it while you can to get extra training done.