mach
Mach is how fast you're going compared to how fast sound is. If you're going like a sonic boom, you're doing Mach 1. If you're going like a lunatic, you're doing Mach 2. And if you're going like a crazy lunatic, you're doing Mach 3.
My car went Mach 2 and my mom’s face looked like it was about to explode.
I hit Mach 1 and my dog’s ears flew off.
My neighbor’s truck went Mach 3 and it broke the sound barrier like it was a piece of cake.