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Fuel additive

I currently use a marine strength Stabil (an ounce for 10 gallons)bought at the local Wally. It seems to have increased my gas milieage slightly from 24 to 26.5 miles per gallon. This was used to offset the 10% ethanol’s apparent detriment to my gas mileage, which nosedived to 22 per gallon during winter month’s where it usually gets 24.5 mpg. I own an older (2001) Subaru. What a car. Beats any of the crap I bought from GM.

Any downside to this use of stabil? Before ethanol I got 28 mpg in the summertime. Ethanol is no solution to anything, mileage, auto wear, or oil reserves, or pollution, far as I can see.

Stabil does nothing for mileage. Everyone’s mileage deteriorates in the winter because of colder temperatures, greater rolling resistance, heavier electrical load.

Ethanol has extended our gasoline supplies by 10% and it doesn’t have to be imported and payed for with money we do not have…There are too many variables that effect gas mileage, driving conditions, speed, wind, load, to make the claims you just did…

Stabil is a stabilizer, not a mileage enhancer. There is no downside to using it, but I don’t think it’s responsible for the increased mileage.

The mileage in my vehicles, including my Subaru, drops if I use E10, but it doesn’t go up if I add a fuel stabilizer.

The only fuel additive (injector and valve cleaner) I use in my 1998 BMW 328i is BG44K. It’s the only one recommended by BMW and independent mechanics. Once in the spring and once in the fall is enough.


Sta-Bil is mostly heavy solvent naphtha. It is also distilled from petroleum and is heavier than gasoline, but lighter than kerosene. If we can find out what the energy expended when burning heavy naphtha is, then we could determine if it enhances gas mileage. One compnent if heavy naphtha is xylene; the others have a similar boiling point.

I agree, an outstanding additive and maybe valuable if increased moisture content because of the added ethanol is a worry. Under those circumstances, if may increase mileage. But then you’d have to be waiting a month or two between fill ups.

BTW… about the GM comment. They may have owned as much as 20% of Subaru when your car was made. FHI is Fuji Heavy Industries parent corp. of Subaru.

On October 5, 2005 Toyota Motor Corporation purchased 8.7% of FHI shares from General Motors who had owned 20.1% of FHI[5] since 1999. GM later divested its remaining 11.4% stake, selling its shares on the open market to sever all ties with FHI. FHI previously stated that there might have been 27 million shares (3.4%) acquired before the start of trading by an unknown party on October 6, 2005, and speculation suggested that a bank or perhaps another automaker was involved.

The Sta-Bil is used in such small quantities (one ounce per ten gallons) that it’ll make about 0 change in mpgs on an energy-content basis, also because it’s only slightly different than the gasoline it’s replacing.

How much does Stabil cost?

Even if it did improve your gas mileage (which I sincerely doubt), once you factor in the cost of the Stabil that you are adding to every tank of gas, are you really saving money on fuel costs?

Like I have previously stated mpg figures are a bragging rights issue,it doesn’t matter what it cost to get that mpg.