Sun Sep 20, 2015 9:00 am by Der Bayer
Cornering grip has been increased by ~15% in order to make track times more realistic (with constant speed through corners currently). As soon as the test track simulation is updated, the cornering grip should be reduced again.
Nevertheless, you are at the limits of the simulation with this build of course. A car with this low weight does not really stress the tyres much. The calculations give the most realistic results with cars weighing 1000-1600 kg. And the car probably does not generate a lot of lift on such tiny tyres with the ride height being pretty low. Looking at the total cost of the car, you probably used some tyre quality as well. How much? +10 would mean that you are running on tyres with quality from 2035. +15 would mean 2045.
So in general, if you put that all together and imagine 15% reduced grip, I think the values are not bad.