More Ethanol In Gasoline: 'Minimal Risk' To Old Cars, Study Says

Follow John

Corn Ethanol Pump

Corn Ethanol Pump

Enlarge Photo

We've written before about just how worried automakers are at proposals by the U.S. Environmental Protection Agency to increase the ethanol content of pump gasoline from 10 to 12 or even 15 percent.

They fear it will damage older cars whose engines and fuel systems were never designed to handle that amount of the corrosive alcohol, and then owners will blame the automakers--not the lawmakers who have mandated a huge increase in U.S. ethanol fuel consumption.

Now a study done by respected auto-technology consultants Ricardo says that, in fact, very little harm will be done to the oldest of cars still on the roads, those built from 1994 to 2000.

Old cars: 1994 through 2000

Earlier studies looked at the impact on cars from 2001 through 2009, but 63 million older cars--which are 25 percent of the vehicles on U.S. roads--had not been evaluated.

The study was for the Renewable Fuels Assocation, a group whose members--not surprisingly--support adding more ethanol, which many of them produce, to the gasoline supply.

Ricardo says that the study showed "minimal risk" to the 63 million cars on the roads from 2000 or before. The company performed its study by focusing on the highest-selling platforms from six automakers whose products made up the bulk of U.S. sales from 1994 to 2000.

With a few caveats--going from E10 to E15 "should not" have an adverse effect on the performance or durability of 1994-2000 vehicles as long as they maintain "normal specifications" and a normal "usage profile"--the study concludes older cars will not be an impediment to the EPA's proposed rule approving up to 15 percent ethanol in gaosline.

Emissions, fuel systems OK

Specifically, a study summary says that assuming the car's engine-management system maintains the proper mixture for optimum combustion, the catalyst should be able to process any exhaust emissions, and evaporative emissions will be the same or potentially lower, since ethanol has a lower vapor pressure than gasoline.

The study also says that the impact of weather, road salt, and other environmental effects on the fuel system outweighs any degradation from increasing the ethanol in the fuel mixture. In a selection of fuel system components from a 1998 Ford Taurus, minor increases in exterior corrosion were seen, but no functional degradation.

In the end, Ricardo says, “The analysis concluded that the adoption and use of E15 would not adversely affect fuel system components in properly engineered vehicles, nor would it cause them to perform in a sub-optimal manner, when compared to the use of E10.”

Fear of failures

Automakers have disagreed, in varying degrees of vehemence, with this conclusion. They fear the wrath of customers angry that their cars couldn't run on a fuel they were not intended to use. Vulnerable components include engines, fuel pumps, and various rubber seals.

The Alliance of Auto Manufacturers reported that fully half the engines it tested had problems on fuel blends that included more than 10 percent ethanol. One problem, it said, lies in the engine-control system that may reduce the fuel content to compensate for a perceived increase in exhaust oxygen due to an extra oxygen atom on the ethanol molecule

The AAM says that could make the engine run hotter, which might damage the catalytic converter, making the car's tailpipe emissions dirtier overall. It might also cause the car's "Check Engine" light to come on, requiring a service visit.

The alliance has not yet responded to the Ricardo study. If it does, we'll give you the blow-by-blow.

Questions remain, but Congress likes ethanol

Ethanol, so the theory goes, can reduce the carbon footprint of vehicle miles, since the plants it's derived from absorb carbon dioxide from the air, meaning that the CO2 released when it's burned is not "new" carbon but has already been removed from the atmosphere during growth.

There are numerous questions about ethanol produced from corn, as it is in the U.S. It is the method with the lowest yield, and the "wells to wheels" carbon balance of the resulting fuel has been widely debated. Concerns over food displacement in agriculture have also been raised.


Follow Us

Comments (5)
  1. Since Congress likes ethanol, but Americans don't like Congress, I don't like ethanol. Maybe I should be getting some of that ag subsidy or PAC money--I bet then I'd like ethanol quite a bit!

  2. Congress likes ethanol because wealthy corn producers like it; no other reason.

  3. With more than $200 billion being sent out of the US economy to purchase foreign oil and the likely prospect of a nuclear Iran, why do we continue bikering about supporting a US industry that is replacing nearly 10% of of our gasoline supply?
    Have you checked the prices of ethanol and gasoline lately? It's been lowering your price at the pump for several years.
    Ethanol won't solve all our energy challenges, but it is a part of the solution. We can do something now, rather than rely on hopes and dreams.

  4. I am from IA - corn country - and I have yet to be convinced that the oil / gas required to process / convert corn into ethanol, combined with the lower mileage I get in my vehicles (which I have checked) actually saves ANY oil / gas per mile I travel. I fear these subsidies for ethanol simply cause more corn to be wasted for no good reason for energy instead of as food, thus driving up the cost of breakfast cereals, etc for the poor in both America and 3rd world countries, as well as the cost of feeding cattle, and thus the cost of steak, ham, etc. The consumer who makes up the tax subsidies is thus the real loser. And energy supporter, it is not the cost of PRODUCING ethanol that is lowering your pump price, it is government SUBSIDIES that the rest of us have to make up. You may unwittingly be supporting an increased WASTE of resources in the production of energy.

  5. To ease any concerns over the fuel vs food debate, we all know by now that this smear campaign was promoted by the Grocery Manufacturers Association as an excuse to raise food prices. With a bushel (about 56 lbs) of field corn going as high as $3.40 in 2007, the consumer saw aproximately a linear $0.02 increase in their retail cereals and related grains. Most food price increases are related to marketing, packaging and transportation, not the cost of the food itself. some more food for thought...for every 2 liter bottle of soft drink, Coke, etc, 1 pound of corn is used to produce the high fructose corn syrup in it.

Commenting is closed for old articles.

Get FREE Dealer Quotes

From dealers near you

Find Green Cars


© 2015 Green Car Reports. All Rights Reserved. Green Car Reports is published by High Gear Media. Send us feedback. Stock photography by izmo, Inc.