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Does ethanol gas harm older engines?

I have been told my some mechanics that ethanol gas can cause increased residue in fuel lines, filters, and injectors.

All of them have qualified their statements by saying that there have not been studies that show this, but they say studies have not used older cars and also the blanket “fuel industry has lots more money than people trying to hold onto old cars.”

Consequently, we have switched to only using ethanol free which also happens to be the most expensive.

Is this a myth?

ethanol gas can cause increased residue in fuel lines, filters, and injectors.

I have never heard that one. If anything I would expect the opposite. Back in the 60’s and 70’s the cars were built not expecting ethanol and it could cause some problems in those cars, but by today the fuel lines etc. should have been replaced.

I will stand to be corrected by the likes of OK, Tester Mountain etc. but I have not heard that one before.

Define “older.” You didn’t say how old your vehicle is.

E10, which is now common, should not harm fuel system components.

E85 is a different story.

I would gladly pay a little extra for pure gasoline if I could find it, because my vehicles get better mileage when there is no ethanol in the gas, but it’s very hard to find gasoline without ethanol in my area.

Define old? The People’s Republic of New Jersey has mandated E10 year round for the last couple of years. Besides a decrease in mpg (5-10%), I noticed my 1993 Caprice (5.0 V8) no longer pings in the summer when the A/C is running. I have had no fuel system related problems since E10 was mandated. However, I can’t speak for any cars older than this.

All things considered, I would prefer running straight gas if I had the option.

Ed B.

It Seems Like I Remember Warnings About Ethanol In Gasoline The Last Time (Several Decades Ago) U.S. Put It In Gas.

I remember manufacturers saying that up to and including 10% was OK, but beyond that damage could result. I remember corrosion (or maybe residue) as being the result.

I’m either remembering this correctly or I’m making it up. My brain is putting out this drvel and it has about an 90% accuracy rate. However, this does not imply that the admonishment was well founded back then.

P.S. I believe Canada, at least Ontario, has been doing this for years. Maybe we can hear from up north.

Does this make sense?

No myth.

Many older (say 15+, depends on make) vehicles have rubber seals and gaskets that chemically break down due to the alcohol in the gas. That causes fuel leaks, fuel pump failures, and potentially fires.

In newer cars, the seals are fine, but 100% gasoline still leaves behinds some residue (termed varnish) in the tank and lines. When you use E10, the alcohol breaks up the residue which then goes to your fuel filter or injectors, clogging them.

So, if you have a newer car, and you switch now, make sure to change the fuel filter afterwords. Keep using E10 and then you will be fine (as long as you drive this vehicle regularly). The real problem is with boats, RV’s, and small engines (lawn equipment). Things that sit for sustained periods without use. For those, don’t use E10 if you can avoid it.

I went through a lot of grief with my 1978 Oldsmobile this past year. If the car sat for more than a day, I had to prime the carburetor to get it to start. I replaced the fuel pump, but that didn’t help. With the age of the car, I didn’t want to buy a new carburetor, and after rebuilding a 1 barrel carbuetor years ago on my 1950 Chevrolet pick-up that took me an entire afternoon to get right, I was reluctant to tackle the job. I finally found an old mechanic who traced the problem to a deteriorated section of neoprene fuel line down by the gas tank. Replacing this line solved my problem and the car starts beautifully. The mechanic thought the problem may have been caused by the ethanol in the gasoline. On the other hand, the deterioration may have been due to the old age of the car. I’m also deteriorating in my old age–perhaps the ethyl alcohol in beer is causing my problem.

Wow All! Thanks for the opinions, facts, and foggy memories! The car in question is a 1998 Chevrolet Metro. Its fuel filter in inside of the gas tank. Were it not in there I would simply replace the filter. I think, though, what I am leaning towards is going out to pay cash for a newer car. Thanks for the help, all.