^ Yeah... Seems like someone is hideing something from us.
Anyway. Well, as you mentioned, your car accelerates better than AI's but then doesn't have as great top speed as they, you obiviously have shorter gear ratios than AI.
You can also test your driving by putting the AI difficulty on pro and use [hard track] setup (because AI uses it as default). If you can get around the track as fast as AI, you probaply don't have any bigger problems with your driving technique. But if you get behind or overtaked by AI you probaply have something wrong with your driving.