Background: having driven a number of cars on a number of tracks, it seems as though the AI setting isn't consistent across cars or tracks. For example, with the Mini JCW, I am consistently 3s/lap faster than leading 90 AI cars. On the other hand, with something like a Ginetta G40 I'm around the same pace, and with a Caterham Superlight or a GT4 I'm around 3s/lap slower than those leading cars. (The obvious difference with those examples is FWD vs RWD so I might need to do some more testing.) My question is, is this my driving style not suiting or being adapted to the different cars, or an inconsistency in the AI? Either way it's fine, whether I need to find a way to extract more from my driving, or to tweak the AI level to suit the car.
Inconsistency by AI. AI calibration for all the classes and tracks in the game is an ongoing process and takes a lot of time. There will be still many classes, that differ in relative pace to player that need adjustments unfortunately. As a help for AI adjustments if you don't have them fitting to your own pace: 1% AI strength above 100% is often worth ~2 tenths at a ~1:30 min. laptime base. Under 100% range it's more like being worth 3 tenths.