09-12-2009, 05:29 AM
It depends on which incarnation. In the 2D games, Tails has always been a fraction slower than Sonic. In games where he follows you, he'll eventually fall off-screen if you're on a long enough straightaway; even in Sonic Advance 3. In the 3D games he keeps pace. In Sonic Adventure 1 because his stages would be impossible if Sonic was continually faster, and in Heroes because he'd suck if he lagged behind every time you were the Speed character.