What is Sonic The Hedgehog's top speed?
His top speed is 765 mph. But what's his fastest speed?
You kind of already answered yourself.
the speed of sound.
The fastest speed of Sonic the Hedgehog was recorded as 761mph nearly mach 3, but its able to keep up. This is totally different from its fastest sound that was recorded as 2,500 mph. Read more on http://sega.wikia.com/wiki/Sonic_The_Hedgehog.