This one's easy. Once more it's just some motion tracking, with our reference for scale being our calculated height for Classic Sonic. However, since Sonic is hunched over in this race we'll lower our height to an estimated 0.6 m, just to account for that difference.
As you can see, their mean velocity during this race is about 115 m/s.
- Sonic Races Metal Sonic - 115 m/s, Subsonic Class
Tidbit: This is actually fairly consistent with our result from the last Sonic CD calculation, with Sonic moving at about 1/3rd the speed of sound without using the Super Peel Out technique and half the speed of sound with it.