I use a lot of additives/treatments and always have. This, along with special oils has given me basically unlimited service on my outdoor power equipment. I know many here shun additives, but check this out; yesterday I saw my neighbor struggling with his mower. This mower has been running rich and sputtering for several years. Even so, it still blows only gas smoke, no blue in it, which is a testament to the Tecumseh engine. Anyway, I couldn't take it anymore, so I picked up a can of B-12 Chemtool carb/injection cleaner and took it over there. I told him to put one ounce in the fuel tank and run the mower. Just an hour ago, I heard the mower running sweet and smooth. I went over there, and sure enough it was the same one. He was amazed. I told him if he had been using practically anything in the gas (MMO, Seafoam, STA-BIL), he would never have had the problem. I didn't even get started on the oil. Bottom line: regular oil and gas are not enough, particularly where E10 fuel is mandated. If everybody used certain additives/premium oils, the repair shops would lose 50% of their business.