What Things Cost: E15 fuel vs. E10 fuel

Newly EPA-approved fuel raises concerns with AAA, auto manufacturers

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In the first of our occasional series looking at what things cost in Eastern Iowa from products to services we did a road test to compare use of E15 with E 10, on our vehicle and our wallet.

So off to the fueling pump with our 2003 Volkswagen Golf we went.

Product: E15

What it is: Automotive fuel with 15 percent ethyl alcohol (ethanol) 50 percent more ethanol than the E10 that has become the most common motor fuel in Iowa. It was approved for use in most newer cars by the EPA in August.

Where to find it:

Linn Co-op Oil Co., 375 35th St., Marion

What it cost:

Nov. 30: $3.11 per gal

Dec. 7: $3.05 per gal

Dec. 14: $2.95 per gal

How it compares to E10:

Nov. 30: 2 cents per gal. more than E10 at nearby stations

Dec. 7: approximately same price as E10 at nearby stations

Dec. 14: approximately same price as E10 at nearby stations

Fuel economy:

Higher ethanol concentrations in gasoline can be associated with a loss in fuel economy. We tested E15 in a 2003 Volkswagen Golf with a 2.0 liter, 4-cylinder engine with a typical fuel economy range of 28 to 32 miles per gallon, depending on factors such as driving conditions, speed, tire inflation, load and weather.

The fuel economy we experienced with E15 was within this range, at 31.5 miles per gallon on the first fill-up and 28.6 miles per gallon on a second fill-up.

Engine performance:

Some groups have warned motorists that E15 use can void warranties on vehicles not designed to use E15, damage engines or otherwise affect engine performance. Because of the age of the vehicle being used for this story, warranty considerations were not an issue, and engine performance did not appear to be impaired. If there was any difference in performance, it was a slight change in the pitch of the engine's sound.


E15 was only available at one location in the Cedar Rapids metro area, Linn Co-op Oil Co. in Marion, which had E15 on only some of its pumps.

E15 can be used in 2001 and newer cars, light duty trucks and sport utility vehicles.

Other issues:

AAA has called for the U.S. Environmental Protection Agency to repeal its approval of E15 because of the warranty issues and also claims that motorists could inadvertently fill with E15, causing motorists to void their warranty or risk engine damage.

We found no evidence that there is any greater risk motorists accidentally would fill their tank with E15 any more than they might accidentally fill with diesel fuel or E85 (the fuel blend with 85 percent ethanol).

Bottom line:

We found no significant advantage or disadvantage to using E15 versus E10, except the disadvantage of having to fuel at one particular location that is less convenient than most. Because of competitive factors in the local market where E15 is available, pricing seemed to favor E10 slightly over E15.

These concerns may be alleviated as more convenience stores begin to offer E15 and prices decline with increased availability. For now, the decision to use E15 may rest on more personal preferences, such as the motorists' views on ethanol and warranty considerations with their particular model of vehicle.

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