Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

E85 Ethanol and older cars (pre-unleaded)

I have a 1969 Ford Mustang - 302 ci V8 engine. The manual suggested using 104 octane hi-test leaded gas. After gas companies stopped selling leaded gas in the early 1980s, I switched to 104 octane leaded aviation gas, which required me to drive to the municpal airport and have the tanker truck pump directly into my gas tank. Then in the 1990s they stopped making even leaded avgas. My mechanic stated the unleaded gas had detergents that if used only would eventually clean away all of the lead build up in the cylinders and engines and could have engine difficulties. A solution at the time is to use octane and or lead booster to the fuel.

The question about E85 ethanol gas is in some parts of the country, gas distributors have again phased out another type of gas, and replaced it with ethanol, making it difficult to find non-ethanol fuel. This is true with where I live (midwest). I have put the E85 gas in the Mustang as it was the only option. I don’t drive it every day, in fact maybe once a month at best and not at all in the winter. I have noticed many more problems since using E85 fuel: My fuel line is clogged with rust deposits and water as it looks like the gas has separated into other component parts. My gas tank is original to 1969 and probably had years of deposits in the bottom. It looks like the E85 has acted like a strong detergent and broken up any deposits and stratifiying them. My engine will hardly turn over and labors with great shaking. I feel the fuel is contaminated and will have to flush the whole system and probably boil out the gas tank.

Here is the question: Does E85 gas cause stratification and or break up of deposits in older pre-unleaded vehicles? Will this ruin my engine? How can a fix the problem? Is there an alternative to E85 gas for older cars/engines or is there an additive that will counter act the build up of Corn based sugar in the gas?

Alternately, I acquired a 1943 Dodge Command Car from Sweden (it was left over from WWII) and used by the Swedish fire department. In Europe they don’t use E85 gas. I would like to solve the E85 gas issue before I tank up this vehicle and have to overhaul its engine too.

You cannot use E85, period, only ‘flex fuel’ cars/trucks can use it. Regular gas will typically by E10, 10% gas. E10 is available everywhere. Are you saying there are gas stations that ONLY have E85? I’ve never seen that. Which engine do you have, exactly? Have you put in hardened valve seats to handle the lack of lead?

I agree that you cannot use E85 at all. The only thing I disagree with is the hardened valve seats. Older cars and trucks do just fine on unleaded gas. In fact…leaded gas was never needed in the first place. There are millions of vehicles built in the leaded gas era that do just fine on unleaded gas. It was a theory back when lead was first introduced into gasoline. The theory turned out to be full of holes.

I’ve heard it both ways regarding valve seats. Either way, it sounds like the fuel system need a thorough cleanout, followed by repairing all rusted items and old rubber fuel lines. My '65 Mustang met a firey end, a fuel line let go in the engine compartment (note, it was then being used by a relative). Not good!

I hope this isn’t one of those questions that get dropped by the OP - this is way more interesting than ‘How often should I change my oil?’

You sure you put E-85 in and not just gas that contains Ethanol?? As stated…you can NOT use E85. You CAN however use gas that contains Ethanol. It’s usually about 10% or less. Which is perfectly fine for you vehicle. If you actually have E85 then drain it…and fill with regular fuel. No part of the country has E85 ONLY.

E85 Ethanol IS NOT Gasoline. It is as bad as using diesel fuel in a gasoline powered car or vice-versa. Any car that was built before about 1990 should NEVER use any blend of gasoline and ethanol. The ethanol is grain alcohol, the same stuff that we drink in whiskey and gin. It is also a solvent, and can dissolve the rubber used in older fuel systems. Yes, it can ruin your engine.

Unfortunatly, OP may not have an option, in many areas E10 is all that’s available.

I wrote the original question and I should clarify for discussion…
I would like to clarify that Gasoline containing ethanol up to 10%, I guess it is E10 vice E85 is my concern; and that is the fuel that is becoming the standard available fuel.
It is hard to find fuel without Ethanol mix in the central US. And the question is whether E10 is harmful to older pre-unleaded gas engines (pre 1980). I see some replies that is is not, and some that it is. This is what I hope to find out: is there a way to avoid it or counter act it if it does harm older engines, either directly on the mechanical or through affecting the hoses, filters, gas tank, etc.

I’ve been using E-10 in my 59 T-Bird, 74 Nova, 89 Mustang GT. and 1987 Mercury Marquis including a lawn tractor, weed eater, chain saw and portable generator for the past 2+ years without any problems to fuel lines or carbs.

NOTHING in the OP’s posts sounds correct. This is a fantasy…Comic book stuff…

The only engine Ford put in a Mustang in '69 that required 100 octane gas was the Boss 302.

100 octane low-lead av-gas is still available at local airports, but they would NEVER pump it directly into a passenger car. For tax purposes, that’s a BIG no-no. You CAN buy it in approved 5 gallon containers after you sign a tax declaration…

If the Mustangs fuel-tank had water in it to begin with, then yes, E-10 might separate as it will not tolerate much water content…

You can buy ONLY E-10 here in NH. There are MANY pre-90’s vehicles running around. I suspect if there was a problem we’d have heard about it by now.

  1. when unleaded gas was first phased in many years ago, it was believed that the valve sealing would suffer due to the lack of lead. That proved to be an unnecessary concern. Old engines from the pre-unleaded days did fine with unleaded, and many are still running.

  2. E10 will not hurt your engine. But E85 will. I’m unaware of any place that sells only E85 and not E10, but if you live in one I’d be interested in learning where that is. The roads are still largely populated with engines that will not accomodate E85.

Ethanol does have a tendency to “clean” things. (even E10) When it was first introduced here years ago clogged fuel filters were common, but after the first tank or two things are usually fine.

We in Minnesota have dealt with ethanol in gasoline since 1992. And we know what it can do to older fuel systems. The corrosive nature of ethanol will eventually damage these older fuel systems.

Because of this, and the problems that arose when E10 was introduced, Minnesota had to pull back the requirement that all gasoline sold in the state had to contain ethanol. This is because you cannot force people to use a motor fuel that damages their personal property. So they allowed some gas stations to sell gasoline without ethanol. The alternative for the state was class action law suit to compensate those who suffered damage to their personal property because of being forced to use E10.

The Minnesota Street Rod Association, which I’m a member, provides a list of gas stations that sell non-oxy gasoline so those of us who drive older vehicles where ethanol can damage the fuel systems have an alternative source of gasoline so this doesn’t happen. Here’s the list.


“This is because you cannot force people to use a motor fuel that damages their personal property.”

You’re lucky to have had the E10 mandate overruled. Most of us aren’t so lucky.

I commend your legislators for overturning the E10. But I respectfully suggest that unfortunately too many times state and federal governments find ways to do all form of mischief that would make the founders roll over in their graves, One of the most immoral, upheld by the U.S. Supreme Cout, was a case where a state took a homeowners property by “emminent domain” to allow a large investment group to buid a big box store. So much for our constitutional protections against seizure by the “state” of private property.

E10 is still mandated in many states. New cars all being designed to accomodate E10, and in many cases E85, I doubt that will change.

One of the most immoral, upheld by the U.S. Supreme Cout, was a case where a state took a homeowners property by “emminent domain” to allow a large investment group to buid a big box store.

I remember that…And the Supreme Court Judge from Weare NH (David Souter) was one of the judges who voted for that. I can almost understand the government taking land for a highway or some other municipal project…But NOT for a private business.

As for E-10…here in NH we use to have MTBE…which is far far worse. May be fine for the car…but it’s LOUSY for the drinking water. Hundreds of wells (if not thousands) have been contaminated with this POISON. Fortunately it’s not too difficult to remove.

There were a lot of doom and gloom scenarios for boats using E10 as well but mine seem to be doing fine. Same with the older cars, small asg engines and such like. I understand that by nature, the ethanol is more corrosive than prior gasoline formations but I just haven’t seen any damage that can be associated with its use.

Now that I’ve addressed the primary topic- I can digress into the other discussion :wink:

I’m no fan of emminent domain or adverse possession laws for that matter. But when one individual can be allowed to hold out over the majority of interested parties, it can be like blackmail. The way you worded it, it sounds like they took the property without paying a fair market value for it. Typcially, under emminent domain, they have to pay the owner a fair price for their property. I only know of a couple instances but the owners in those situations were paid market value and then some to make the deal go through faster. At what point do you draw the line when one person is holding up the entire process? When do their demands exceed normal and reasonable compensation?

Under eminent domain it can only allegedly be taken for the public good, and in NH it has to be “blighted” land. If I recall correctly the land in question was in Rhode Island.

I draw the line firmly at taking the land for commercial development. Nobody should be forced to sell their home for any amount to make way for the developmnet of commercial enterprize. Ownershp of property by a private individual is a fundamental premise of a free society. Government forcing us out of our homes to use the land for other than public use is heresy, even if they pay “fair market value”.

If a private enterprize wants to buy my house to develop a commercial property and I want to “hold out” for an unreasonable price, that’s between me and them. The government has no business intervening. Period. It’s my house, more than that it’s my HOME, and I should be able to demand whatever I want…or refuse to sell if I choose to stay.