@Chrono Z: Yeah, they do. Take the Mario Kart series: The cars are quite a bit slower than the bullet bills, which have been seen repeatedly to be MUCH slower than the Mario Brothers. In Super Paper Mario, it's possible to see that the brothers are capable of running faster than sound. The land speed record is just above the speed of sound. So, Mario and Luigi are faster than cars.
@Chrono Z: Bullet Bills are faster than karts, but slower than the Mario Brothers. That is what I meant.
The games never pretend that they're normal, quite the opposite, it's been defined a few times that they aren't. They are human, but they aren't ONLY human.
Sonic 2: It's in the manual.
Sonic Adventure: Tails beats Sonic repeatedly in a race.
Sonic Colors: Sonic can't move fast enough to pass Tails.
Almost every game: Tails flies behind Sonic as he runs without falling behind.
@Chrono Z: Most of what is known is in the manual, all of the characters feats are done while they're being controlled. That holds true for EVERY video game character.
...Seriously? Fat and slow?
No, I didn't contradict myself. Tails is behind because he's following Sonic. Relative to Sonic, he stays in the same place, so he must be moving at the same speed.
Also, please don't assume you know how I might react to things.