Study: E15 poses little risk to older vehicles

By Kris Bevill | August 27, 2010
Posted Sept. 15, 2010

A study recently completed by international automotive engineering and consulting firm Ricardo Inc. shows that the use of E15 in vehicles produced in model years 1994 through 2000 poses minimal risk of damage to those automobiles. The study, funded by the Renewable Fuels Association, was conducted to demonstrate that a partial U.S. EPA waiver to allow E15 use only in vehicle models 2001 or newer is not necessary and that E15 can be used in older model vehicles with no adverse effects.

During a news conference to announce the study results, RFA President Bob Dinneen said the organization has been making its case for a full E15 waiver for months, but current indications are that the EPA will grant a partial waiver because the data it has received focuses only on newer vehicles. The EPA is expected to issue its decision sometime in September and RFA intends to make the results of this latest study available to the agency before it makes the final waiver decision.

The ethanol blend wall continues to be one of the most difficult challenges facing the ethanol industry and a partial waiver will not provide enough relief on supply issues, Dinneen said. Additionally, allowing E15 use only for certain vehicles will likely cause confusion among consumers. "We've been concerned about a partial waiver," he said during the news conference. "We have very deep concerns for the confusion that it might create in the marketplace for consumers and certainly for gasoline marketers, and we are concerned that as a consequence the market opportunity for ethanol resulting from a partial waiver would not really be what we need. The bottom line is if the agency is going to allow E15 to be used because of their evaluation of 2007 and newer or 2001 and newer vehicles, that the change from E10 to E15 is just not significant enough to not allow that for older vehicles as well. There's simply no need to issue only a partial waiver."

According to Ricardo, vehicles manufactured during model years 1994 through 2000 represent roughly 25 percent of all U.S. light duty vehicles currently in use. Ricardo identified six manufacturers that represented the majority of vehicle sales for that time period and focused on the top 10 selling platforms from those manufacturers for its study. The firm then evaluated several technical areas, including fuel system changes, various emission and diagnostic regulation levels and certification data, after-treatment systems, and vehicle calibrations. Physical fuel system parts were also obtained and evaluated for evidence of deterioration.

The primary risk of using E15 rather than E10 is the potential for leaks in the vehicle's fuel system due to metal corrosion, swelling in elastomers and/or hardening of plastics. Ricardo's study concluded that vehicles produced during the 1994-2000 time period would not experience negative changes if the vehicle were to be fueled with E15. In fact, Luke Cruff of Ricardo U.S.' gasoline and spark ignited product group said physical fuel system components acquired for the study showed greater deterioration of equipment on the outside, stemming from forces such as salt and moisture. The portions of the fuel systems that were exposed to E10 showed little deterioration and Ricardo said it expected no further degradation would be experienced when similar systems are exposed to E15.

The 89-page report can be viewed in its entirety at