It is a stabilizer, cleans carbs and fuel injection,cleans carbon build up, lubes upper cylinders,removes moisture,and works as an anti-gel. And this is just by adding it to the gas. My outboard is fuel injected and I always use it through the winter, and if I don't get a chance to get the boat out, it was recommended to me as a winterizer for my engine. If you have a carb engine you can use a spray bottle and go straight through the carb and clean it and often you will notice it idling smoother instantly. This is some great stuff. You can even add it into the crankcase of your vehicles and clean the oil ports, lifters, rings and etc.It can even be sprayed into your air intake system to clean things out there as well.