Thursday, August 28, 2008

Is this the "damage" that E85 can cause in a non-flex fuel vehicle?

E85 is a mix of 85 percent ethanol and 15 percent gasoline. Unless your car or truck is designated as a “flex-fuel” vehicle you should not use E85. If you run E85 in older cars (pre-1995 that are designed for gasoline) then your car may be severely damaged. It can cause damage to seals and hoses along with causing corrosion throughout the fuel system. It can also wash lubrication off the engine’s cylinder walls. The hydroxyl group on the ethanol molecule is an extremely weak acid, but it can enhance corrosion for some natural materials.

For ethanol contaminated with larger amounts of water (i.e., approximately 11% water, 89% ethanol), considerable engine wear will occur. This wear is especially harsh during times while the engine is heating up to normal operating temperatures. Just after starting the engine low temperature partial combustion of the water-contaminated ethanol mixture takes place and causes engine wear. This wear, caused by water-contaminated E85, is the result of the combustion process of ethanol, water, and gasoline producing considerable amounts of formic acid (also known as methanoic acid). In addition to the production of formic acid occurring for water-contaminated E85, smaller amounts of acetaldehyde and acetic acid are also formed for water-contaminated ethanol combustion. Of these partial combustion products, formic acid is responsible for the majority of the rapid increase in engine wear.

Engines specifically designed for flex fuels employ soft nitride coatings on their internal metal parts to provide resistance to formic acid wear in the event of water contamination of E85 fuel. Also, the use of lubricant oil (motor oil) containing an acid neutralizer is necessary to prevent the damage of oil-lubricated engine parts in the event of water contamination of fuel. Since older cars are not protected from formic acid the use of E85 is not recommended.

6 comments:

Anonymous said...

First- where would one ever get E85 with 11% water???? In the USA- fuel grade ethanol is not allowed to contain greater than 0.8/10ths of a percent H20. Even hydrous ethanol such as has been used for years in Brazil was typically only 4-6% H20 and that was even used in the earlier years in converted engines not originally made for ethanol.

Second- The only automaker who required a special oil (Daimler) has since dropped that requirement. To my knowledge all oils contain base (used to be called TBN- total base number) to neutralize acids. Diesel oils in particular are loaded with this due to the sulfur content of the fuel but today the gasolines are higher in sulfur than diesel. When you burn hydrocarbons you get water too and when combined with poorly combusted gasoline loaded with sulfur you get-- sulfuric acid. This is why short trips are so hard on engines in cold weather (besides lack of oil film at start up.)

As far as cylinder wash goes- An FFV is programmed to dump more fuel in cold start open loop than you will ever see with a non-ffv. If cylinder wash is a problem then it should be showing up in my Taurus with 183,600 miles with all but <20,000 miles on E85. It uses not a drop of oil between 4-6,000 (a few times 8,000) mile oil changes on Ford's plain old everyday too light 5w-20. This is a very wet engine too- burning E85 generates soo much water that it keeps the tailpipe washed clean- you can never get even a tinge of carbon on a "swipe of the pipe".

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buzzcut said...

Al, blogger does not let you post files.

If you wouldn't mind, could you e-mail me the file?

eric dot krieg at sbcglobal dot net

From my years in automotive engineering, I'm the master of looking at engine data. I promise to post some awesome graphs and whatnot.

buzzcut said...

Al, your Taurus has 186,000 miles, and you'r complaining that 5W20 is too light?!?

I think I'm going to switch! I'll take a 2% mileage improvement if my engine lasts "only" 186K miles!

Anonymous said...

Buzz- I will email you with the files if you want- However, not sure you want the whole thing since I did 45 frames on each fuel at light cruise and another 45 frames each fuel at heavy acceleration. Acceleration runs are iffy because they are so short I missed peaks between frames and would have to shut down in seconds to avoid speed/control issues.

As far as the Taurus- I was developing a lifter tick (likely due to extended drain intervals more than 5w-20) so I first hit it with 1/2 quart ATF and tick was gone in <75 miles. Next I went to a strong detergent 10w-30 synthetic diesel style oil which I will drop before cold weather. At that point I will go back to 5W-20 for mileage and cold start oil flow. I am not really afraid of 5w-20 in that engine though I do feel it is on the light end. The old 3.0L engine in this is rock solid, of durable design, and should easily make 300,000 miles. I would not use 5w-20 in my Saab though.

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buzzcut said...

If it's not too much trouble, please e-mail me the files. I'd like to take a look.

Do you think Ford did anything to harden the bearings or something to run on 5W20? If not, why doesn't everybody use 5W20 (not just Ford and Honda)?

I know that it's not a huge difference in fuel economy, but every % counts! And if it isn't going to give you trouble until 180K miles, what's the harm?

Not an issue for me, as I get oil changes for free by Saab.

Anonymous said...

Buzz- the oil people I used to work with claimed that Ford used 5w-20 purely for MPG ratings. Not sure about that but that was the "buzz" at the time it came out.

I will see if I can get that email out tonight.

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