Hi, I’m new to the forums and this is my first post. The drivatars in this game are the worst i’ve seen in any Forza games. They are inconsistent with their difficulty, regardless of what difficulty you choose at the start of each race; some races I can comfortably win first place without breaking a sweat while others make you feel like some of the drivatar cars have a rocket strapped on the roof. When the game decides it wants to make it difficult it does so to an extreme degree. Playing on “above average”, I noticed that some drivatars posted lap times that were worthy of being at the top of the leaderboards (I understand that there aren’t many players playing right now). I’m no professional gamer and or race car driver but this seems excessive, especially when lowering the difficulty doesn’t seem to make a difference. Anyway, I know some people have probably already mentioned their issues with the drivatars but I felt obliged to share my opinion on the matter, considering I spent $100 on the game. Besides the AI difficulty/being cheap, Forza 6 is a pretty great game!
Try adding people from rivals mode whose times are more akin to yours. The game seems to ensure that it matches a few friends even if those friends drivatars are far better. The more Forza friends you have across varoious difficulties the easier it can choose appropriate competition 
Thanks for tip, will try it out.