guy's i'm not preaching that you have to run this stuff but i can with pictures in the future prove that it works. whats a few extra bucks for someting that wont let any carbon generate in the cylinder. this stuff didn't become popular untill the direct injected engines became popular in the late 90's. the injector is in the top of the cylinder head that way the exhaust port is completely closed before the fuel is given to the cylinder. bad part is the injector is in the worst spot for carbon, top of the head. so these expert bass fisherman who spend hundreds in baits wont spring a few extra bucks for the oil that is required for the engine. so after a season of wal-mart super-tec which doesnt clean like a good detergent oil, the injector clogs with carbon and smokes the powerhead becuse it runs lean. then i get to hear about their 500 dollar a month boat note, 700 hundred dollar truck note and how they cant afford to fix the motor. a month later the bank calls me and says lock up the boat! moral of the story is spend 15.00 bucks every two years for 16 ounces of insurance. whats it gonna hurt to have something in the gas that PREVENTS carbon build up. jeff