Gumout 510023 Regane High Mileage Fuel System Cleaner, 6 oz. (Pack of 6) (510023W-6PK)

We have older cars with higher mileage and this stuff seems to do its job, we've had no issues and no complaints. Very easy to work with!

Works great for cleaning fuel system. I use it in all my gasoline cars and trucks.

Reorder additional. Package had no leakage. Great value for the price and quantity. Seems to help with my mileage at 178k, using every 3k.

Backstory, I should have used fuel system earlier in my car. At about 120k, the engine started knocking, especially with the AC running. I have used predominantly Sam's Club gas, 87 octane. I never used fuel system cleaner until then (I have in my other cars, but just never did in the Prius. With the gas practically empty, I put in a bottle and only put in 4-5 gallons of gas. It definitely helped with the engine knocking. I now use it regularly (everytime the engine starts knocking again every few thousand miles.) I did originally try this on an empty tank and filled it up the tank......did not stop the engine knocking. Thus now I only put in a few gallons. Did it improve mileage....NOPE. I did not see any performance increase.

I started using this when my Audi was burning oil from a problem with carbon buildup around the piston rings. Tried other additives with no luck and I use top tier fuels. Tried this on a friend’s recommendation and it cut down my fuel consumption and increased my gas mileage. I have been adding a bottle every other fill up for the last 6 months and sustained my results. Very satisfied and will continue to use.

I used 6 of these every fill up crossing the country. My Explorer has about 80K miles and although I didn't notice much from off ramp to fwy., when I arrived and started driving a few days later it was like a new car., fast starts, responsive, and my mileage has gone up.. performance improved significantly. Yep, impressed., a 29 dollar tune up.

I do my own oil changes on me and my wife's car and I add one of these with every oil change in the beginning I did three in a row the gas mileage improved

Because this is one of the few products that I am aware of that contains PEA's (Polyetheramine) I use this product in all my vehicles every now and then to clean out the injectors and intake valves to prevent carbon build up.