OMAHA, Neb. — A new pilot-scale study on ethanol fuel efficiency suggests improved fuel costs for cars at 10, 20 and 30 percent of ethanol in petroleum. The American Coalition for Ethanol, holding its 18th annual convention and trade show in Omaha, unveiled the results of a commissioned pilot study.

Allen Kasperson, a fuel research specialist and former instructor at Lake Area Vocational Technical School in Watertown, S.D, designed and ran the test.

ACE commissioned the study to collect data in advance of a 20 percent mandate on ethanol use in Minnesota. It did not include E85, the 85 percent blend of ethanol. The short-distance test was in three late-model vehicles.

The tests were run at 70 mph on 300-mile tests on Interstate 29 between Watertown, S.D., and Brookings, S.D.

Each vehicle used a "data logger" from the vehicle's engine to a laptop computer. The device measured fuel consumption and any other performance issues.

Brian Jennings, ACE executive vice president, says the study is an important counter- weight to often-errant media reports that often denigrate ethanol.

"Last evening, on Headline News' on CNN, one of the bits of advice for fuel efficiency was to not buy gasoline with ethanol," Jennings said, speaking to the group at its first program day on Aug. 17. "We've got to get the word out and the facts straight."

Kasperson compared results with five fuel regimens, showing only slight declines in fuel efficiency, but lower costs per mile for ethanol. Among the primary observations:

1) Ethanol blends produced slightly lower average gasoline mileage, compared with unleaded: E10 -- 1.5 percent poorer mileage. E20, 2.2 percent lower; E30 -- 5.1 percent lower; E10AK (10 percent ethanol denatured with iso-pentane and biodiesel).

2) Because the cost of ethanol was lower than the cost of gasoline, the cost per mile of operation generally was lower when using ethanol blends. At the time of the test, ethanol and unleaded was just under $1.60 at the time of the study.

Average results were: unleaded, 7.08 cents per mile; E10, 7.0 cents per mile; E20, 6.85 cents per mile; E30, 6.88 cents per mile; and E10AK, 6.79 percent per mile. Put another way, $20 in fuel would allow driving 282 miles using unleaded; 288 miles with E10; 292 miles with E20, 291 with E30 and 295 with E10AK.

3) No warning lights were displayed at any time on the vehicles during the test. The computer monitor showed no malfunctions.

4) In all vehicles used, the cars adjusted the air-fuel ratios normally.

Details from individual cars in the study were:

--2005 Chevrolet Impala with a 3.4 liter engine: Showed just over 1 percent lower mpg on E10 and E20, but actually gained .6 percent mpg when operating E30 and over 5 percent on the E10AK blend.

--2005 Ford Taurus, 3.0 liter engine: E10 provided almost 4 percent less mpg than unleaded; E30 was 5 percent lower. This was the only car that showed a reduction using E10AK. It performed best on E20 -- 0.7 percent lower than unleaded.

--2005 Toyota Camry, four- cylinder engine: Showed virtually no variance between unleaded and either of the E10 blends, but both E10 blends performed better than straight unleaded. This car also took the largest drops on fuel efficiency when using E20 and E30. Kasperson says the company's "tight" tolerances for optimizing efficiency of standard fuels like unleaded and E10 also could result in larger variances for nonstandard fuels.

The only ethanol blend that tested poorer in cost per mile than the unleaded gasoline was E30 in the Toyota Camry and the E10 and E30 in the Taurus.

"In general, the more ethanol used, the lower cost per mile," Kasperson writes.

Using average miles per gallon, E10 is a less expensive fuel than unleaded until ethanol's cost is 28 cents per gallon above unleaded, according to the study. At one point during the test, prices of gasoline and ethanol were far enough apart that E10 was 4 percent less expensive, and E20 was almost 13 percent less expensive.

E10AK -- seen to be a potential ethanol-based "premium" fuel -- showed less savings in the low-ethanol price scenario, but that would improve if the fuel were made on a more consistent basis.

ACE can't recommend consumers using higher than 10 percent ethanol, according to the study report. ACE acknowledges the test is a small one but suggests that a larger and more detailed study is in order. Studies also should compare E-85, the 85 percent ethanol blend, to unleaded.

Currently, the miles per gallon with E85 are "assumed to be" almost 30 percent lower, while "anecdotal evidence" indicates that actual performance is better, according to the research report.

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Source: Knight Ridder/Tribune Business News