Gumout - Concentrated Fuel System Cleaner, 12Oz

When I went to buy Spark plugs, they sold the Gumout to me.

Does it work? Is this a good brand?

My tank is 10 gallon (bottle says up to 20 gallon tank). Can I use the whole lot?

I am considering whether or not return it?

Unless you have a specific problem that you think may be related to fuel contamination then you don’t need it.

However, even on a good running car it does not hurt anything to run a bottle of cleaner through it about once a year. Yes, you can use the entire bottle.

Gumout is ok, just like a lot of other cleaner. My preference is for SeaFoam or Berryman B-12. The price of SF really jumped up a few years ago (close to 10 bucks a can) so I use the B-12 when a product may be needed.

Menards in my region has Seafoam for $6.50 a can.

Agree. Can’t hurt. Might help.

It won’t hurt anything but it’s unlikely to do any good, either.

ALL gasoline has fuel system detergents in it by federal law. Under normal circumstances nothing else is needed.

Under normal circumstances. I would point out my brand new 2011 Hyundai Sonata specifies either using Top Tier fuel all the time or using an approved cleaner at every oil change. Apparently, direct injection engines are picky about their gasoline.


What is “Top Tier” fuel? 93 octane? Good luck with that, Hyundai owners.

It’s a designation given to a number of brands of gasoline meeting certain requirements re the amount of detergents in the gasoline. It has nothing to do with octane–the Sonata uses regular octane gas like any other base sedan. Chevron, Shell, Exxon, Mobil, Texaco QuikTrip, and a number of others are Top Tier. Arco thus far hasn’t got this designation.


There are two reasons I am not totally against fuel system cleaning and fuel system cleaners. It was common durning the earlier days of fuel injection systems to pull the injectors and put them in a test fixture. One of the things you were looking for is a well atomized spray pattern (one with no droplets and no “streams”). Second, GM supports fuel system cleaning, but they only offer support for their products or techniques.A poor spray pattern or one that is not well atomized is a sign of a dirty injector.

That being said I really object strongly to the way high cost of “full on” fuel system cleaning and consider the “add to the tank” product to be a good compromize.