Today's gasoline breaks down quickly. When it does, it leaves behind a thick varnish-like residue that adheres to the walls of its container, including the inside of the fuel system in your lawn equipment. Further, "regular" gas may have 10%, or more, alcohol, which attracts and blends with water, causing carburetor problems and the breakdown of lubricating mix-oils in 2-cycle equipment. Lawn equipment is especially prone to these fuel problems because the equipment is not run daily allowing time for the fuel to deteriorate and absorb water. For best results, avoid alcohol-blended fuels in 4-cycle lawn equipment and never use high-alcohol blends in your 2-cycle equipment. "Mid-grade" and "premium" fuels generally are not blended with alcohol.