Well, if you live in a state where they add a lot of ethanol to fuel this might be worth buying. I don't know all the chemistry, but to put it technically, ethanol body-slams your carburetor. Here in NJ where they add a ridiculous amount of ethanol to our fuel if you leave that crap sitting in your equipment without any additives it will trash the fuel system. I had to have my mower fuel system cleaned out this year before it would run, and the guy at the small engines place clued me in to what ethanol was doing to my equipment. The repair cost $50, and I now use an additive he recommended to prevent the problem.