Is alcohol in fuel good or bad?

Photography Credit: Stuart Garage/Unsplash

Most fuel sold these days, whether it’s for street or competition use, contains alcohol–ethanol, technically. Is that good or bad? As usual, the answer is “it depends.”

More Power Potential:

Fuels containing alcohol have the potential to generate more horsepower since they burn quicker, explains Zachary Santner, senior specialist of quality at Sunoco. “The science says that the E15 is worth it because the fuel contains more oxygen.”

That doesn’t necessarily mean that running an oxygenated fuel will instantly increase power. However, an engine can be tuned to take advantage of that alcohol–and that’s why it’s a component of many race fuels. 

Sunoco’s popular 260 GT Plus contains 13 percent alcohol, and the product description includes a bit of a heads-up: “Due to its high oxygen content, an increase in fuel flow is required to utilize the full potential of 260 GT Plus compared to conventional non-oxygenated fuels.” 

Need even more alcohol? Sunoco’s Green E15, the spec fuel used for the Monster Energy NASCAR Cup Series, contains 15 percent alcohol. “When NASCAR switched from a non-ethanol fuel to Sunoco Green E15,” Santner says, “all the teams were able to pick up horsepower.”

More Moisture, Too:

Alcohol has a downside, too. Over time it will absorb humidity from the air and draw moisture into the fuel system. As many classic car owners have learned, that moisture can and will play havoc with carburetors, fuel pumps and other components. It’s not pretty, as things corrode and get wonky. 

Some corner stations carry non-ethanol fuel. It’s not a common item, but offers a directory. 

If you need a non-ethanol fuel sporting more octane than the usual, there’s also Sunoco’s 260 GTX. It’s a 98-octane unleaded race fuel that works well in high-compression, smaller-bore engines. Sunoco also recommends 260 GTX for forced induction. Note that legally, this non-ethanol product can’t be sold for street use.

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wspohn SuperDork
3/31/22 11:25 a.m.

We are lucky- in my corner of Canada, I can get non ETOH added 94 octane  (every time I go South of the border, I have to Bob Costasfoot as imy daily driver is tuned for the 94 and boosts at 25 psi).

The alcohol added fuels are a PITA on old cars that sit for half the year, and get no benefit from the alcohol without retuning.

Coupefan Reader
3/31/22 1:17 p.m.

1.  Good.  Reducing our dependency on oil...anyone's oil, and its global issues.

2.  Bad.  Using farmland that should be growing food instead of fuel.

3.  Bad.  Unforeseen maintenance issues with fuel components. 

4.  Bad.  Farm subsidies could be used better in other places.

5.  Good.  Pre-detonation control might save an engine or two.

frenchyd MegaDork
4/6/22 8:09 a.m.
The Staff of Motorsport Marketing said:

Sponsored content presented by Sunoco.

Most fuel sold these days, whether it’s for street or competition use, contains alcohol–ethanol, technically. Is that good or bad? As usual, the answer is “it depends.”

Read the rest of the story

Good. Your engine won't have the same deposits in the combustion chambers and on the back of intake valves as straight gasoline. 
 Good. Your engine will run cooler  

Good.  correctly tuned it will have slightly more power.                                                                                

  Actually water has always been in Gasoline. It collects in holding tanks all the way from the refinery to the gas station and eventually your cars tank. They are all vented to air. Air naturally has some moisture in it.  It's called humidity. 
Early fuel pumps would display the fuel in a glass container so the customer could judge for himself the suitability.  Later glass bowls were added to the fuel lines so owners could drain out excess water. 
   Eventually the gas companies convinced the manufacturers that a small amount of water was good for the engine.  It reduced  Knox  and cleaned out combustion chambers. 
    Collectors of vintage cars should know how to adjust their car  for oxygenated fuel.  A slight richening of the fuel and some additional timing will regain most of the lost fuel mileage.  Anything with modern fuel injection will self adjust.  Alcohol is not going away as long as Iowa starts the political season. 

David S. Wallens
David S. Wallens Editorial Director
4/7/22 11:23 a.m.

In reply to wspohn :

Just curious, what's the price premium for that non-ethanol 94? 

Don2001l New Reader
11/9/22 6:33 p.m.

I paid $1.88/L Canadian last weekend for 91 !

x 4.54L per Canadian gallon 

x  3.785411784 L per US gallon

x your exchange rate 

Not Cheap !!

David S. Wallens
David S. Wallens Editorial Director
11/11/22 11:31 a.m.

In reply to Don2001l :

Not cheap. Last time I bought non-ethanol 93 here, I remember it not being inexpensive as well. 

I was buying 91 non-ethanol but, since I'm driving the cars more, have just been running premium lately. 

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