Gumout 510011 Multi-System Tune-Up, Fuel Stabilizer Injector Cleaner & Gas Treatment, 16 oz, Full Fuel System Cleaner - Improves Engine Performance, Cleans & Removes Deposits and Residue

What else is there to say? This is a great multi-purpose product that has been a mechanic's choice for years. It works exactly as advertised—cleans the fuel system, helps reduce rough idling, and can even improve mileage with regular use. I've used it in both gas and diesel engines without any issues. Definitely a solid value, especially when buying online—much cheaper than what you'll find at most big box stores. If you maintain your vehicles yourself, this is one of those must-have items on the shelf.

I've used Gumout Multi-System Tune Up for both my cars and small engines in my lawnmower and generator. It seems to clean the system and improve performance very quickly. I tend to use it every 7k to 10k miles in my car and with every tank in my lawnmower and generator.I especially like the fact that it is supposed to be a fuel stabilizer as well as clean the system. This has been important to me for my lawnmower and generator. Prior to using any sort of additive in my lawnmower, I had left fuel in the tank over one winter and the next Spring it would not start very easy and would run rough. I added a significant amount of Gumout to the gas and ran it about 5 minutes, though took a while to start was still running rough. Tried it again the next day and the mower worked like new. I can only imagine that the Gumout got worked into the fuel system the day before and it cleaned out the gummed up ethanol overnight. Now I add about 1 oz of Gumout to each gallon of gas for my lawnmower. Since then, it runs perfect with no problems, even when leaving gas in the tank over Winter.For my car, I can definitely notice improvement in performance after using about a quarter tank of treated gas. I am not sure about the level of PEA in the mixture, but it seems to be enough for a mid-size car with an 18 gallon tank. For large vehicles, maybe two can would be necessary.The only thing I don't like about this product is the can. I know it is modeled after the Seafoam container, but it is difficult to use when adding to a car gas tank. Other Gumout products have long neck designs that make adding to the tank easily, it would be nice if this product had that design too.

I buy cases of this stuff to run in all my fuel tanks on everything and add it to my oil too. My engine runs smoother and I get 1-3mpg on the hwy when I run it in both my oil and fuel.

Works very good

This is the best product we've found for engine performance! We have tried other brands, but this is the best solution for removing gunk from the fuel tank. Highly recomment!

Ii put the full bottle in my oil and ran my car in idle for 20 minutes and now my car has more power on acceleration and runs smoothly.

Seems to work but u have to use it regularly like once in 3 or 6 months

This stuff works great! I’m a mechanic with over 35 years experience and this is my favorite go to for small engines.I recently restored a 1994 Kawasaki Vulcan 750 after it sat for 16 years.Cleaned the carburetors in the ultrasonic cleaner and rebuilt them.The bike was re-jetted for a Aftermarket exhaust and air filters.After getting the bike to run it still had a fuel delivery issue the the front cylinder carburetor and tried various other products hoping I wouldn’t have to remove the carburetors again because it’s not a fun job,nothing seemed to help much as the engine wouldn’t rev out completely.I added a few oz of this product to the fuel tank and the bike let it warm up then held the throttle wide open and it started to rev out and eventually it cleared up and now revs out completely.There must have still need a blockage of some sort in the main Jet circuit of the carburetor and the gumout cleared it out.