Video: Airplains' Inpulse Anti Detonation Injection
Although a lot of aircraft engines are approved to burn mogas, that doesn't include many high-compression, high-horspower engines like the Continental IO-520. That's where the Airplains ADI system comes in. It injects a water/methanol mixture into the induction system to allow the burning of lower-octane auto gas. Here's a video tour of the system.