Sonic using Mach Speed
A Super Sonic Boost Dash that briefly increases speed
Mach Speed is a move used by Sonic the Hedgehog that has only appeared in Sonic the Hedgehog (2006) as one of Sonic's custom moves. It is a move that gives Sonic a short boost of speed. It can only be used after Sonic obtains the Blue Gem. It is a variant of the Mach Speed Sections found in certain levels.
In order to use Mach Speed, Sonic has to possess the Blue Gem upgrade. When Sonic is in possession of it, the player has to select the Blue Gem with the directional pad and can use it by pressing Right Trigger/R1 button.
When using this move, Sonic can perform a "Super Sonic Boost Dash" that makes Sonic perform a fast, but very brief dash that increases his speed to its maximum. If Sonic runs into an obstacle while dashing however, he will fall down on the ground for a second. Despite some fan beliefs, it is not to be confused with the game mechanic variant. This move is nearly identical to the game mechanic, but Sonic doesn't lose rings when he touches something.