RDG

I was filling up my car the other day and on the pump was a sign that said that the gas contained 10% ethanol. I have heard that a larger percentage of ethanol may start be used. I'm thinking that the only negative effect ethanol might have is on sensors and converters and since my old Olds doesn't have any it should not be a problem. I know someone out there in Oldsmobile land will have the answer. Thanks and have a great day.

Olds64

This has been discussed at great lenght before. I have never seen any scientific evidence that ehtanol blended gasoline harms older vehicles. I've heard many times that the ethanol damages rubber seals and gaskets in the carburetor; however, I've never experienced it. Plus, I've been running 10% ethanol blend gasoline in my Oldsmobile for a number of years. If you maintain your car properly you won't have to worry about it anyways. Ethanol is just another additive put in gasoline like tetraethyl lead or MTBEs.

joe_padavano

The proposed increase in ethanol content was voted down in the most recent attempt to get it incorporated, but the EPA and the farm lobby are continuing to push for it. SEMA has been very vocal in trying to prevent this. Join the SEMA Action Network for regular legislative updates.

Bluevista

I unwittingly put some in my GTO and the washer at the fuel line fitting to the carb started leaking within 10 minutes.

citcapp

10% ethanol is mandated in Washington state during the winter months. Can't get around it. So far no problems.

RDG

I guess I should have known that this must have been discussed some time before but I just missed the previous tread(s).
I have used ethanol blend in all my older stuff - tractor, saws, generators, etc and never really thought about it or its affect on gaskets and O rings and such. I know my Honda book specifically states that 10% ethanol is ok and I figured it must have to do with sensors and converters. Thanks for the info and sorry for re-inventing the wheel!

oldcutlass

I try not to use ethanol in my older cars, luckily there is a Phillips 66 station here that swears on ethanol free gas. How do I know, you ask??? Well, the fuel economy on ethanol is 15% less. I use the wifes late model GT Mustang as a running test. With unleaded she gets a consistant 21 - 22 mpg, and 10% ethanol she gets 18 - 19.

Joeypete

Yeah it is getting hard to avoid it now as it is mandated in many states. Every gas station I go to in town uses E10. I use E85 in my Focus sometimes and I love the stuff but I'd be cautious with an older car. Any car built after 1980 however will be fine with E10 or probably E20 even, but you don't see high mixes like that, except at blender pumps.

marcar1993

Ethanol is great in older cars to be run in about a 10% mix in maybe a tankful to clean out the fuel system. Not continuously... It WILL eat seals and it WON'T be metered properly by a carb setup for GAS.
Gasoline has an optinimal a:f ratio of 14.7 Air : 1 Fuel. Alcohol is supposed to have much more fuel than gas in the a:f ratio. So it will cause lean issues. If you notice, alcohol burning cars have carbs set up different than gas. They have bigger jets and have non rubber seals. Alcohol in prolonged cases or with old gaskets will eat live rubber parts.
On that note, all they have in my area is E10 and I have no choice but to run it.

66ninetyeightls

Any ethanol over 40% will also begin eating electrical contacts and fuel lines. Thats why most E85 rated vehicles have magnetic fuel level sensors instead of a potentiometer.

OLD SKL 69

That is exactly why I have had to change the metering rods in my Cutlass carb, the jets in my Riviera carb, and the jets/rods in other carbs I service for some friends. Hesitation off idle has been the main culprit with the new gas. Other than that, I have not seen any issues with the rubber seals being destroyed...yet.

oldss72

stoichiometric for E10 is 13.5/6ish. Just fyi, it also lowers the Lower heating value of your fuel. It is not a big deal, but should be noted if you are really trying to be technical and theoretically calculate the output of your engine.

compedgemarine

one thing to keep in mind, there are no regulations on the ethanol quality or content. only the gasoline portion is regulated. in winter E85 is really only around 60 or 70 percent ethanol. if not the cars would not start. ethanol which is just alcohol is highly corrosive and also traps moisture. when racing on alcohol you have to drain it and run gas through the system to keep the alcohol from destroying the seals and aluminum fittings.

Snowdog

I guess we will have to cross the border
to Mexico,Long ride for me, Give me GASOLINE

ROBMON

Avoid it if you can. It isn't required in prem. in Mo. Most sta. are adding it thou, SGNAL is one that has ethanol free in prem. only. You lose milage & many other things. NO GOOD!!!!

jaunty75

These are put in for very different reasons, though. Lead was added many years ago as an octane enhancer to prevent knock, and it turned out to have the positive side-effect of protecting valves and valve seats. It was never added as any form of pollution control material, and in fact was itself a heavy source of pollution. One of the great advantages of lead, though, was that it needed to be added in only very small amounts (1 part in 1260, according to Wikipedia) to be effective, so adding it did not dilute the fuel content of gasoline. It has long since ceased to be a part of the gasoline we buy. MTBE and ethanol are also octane enhancers, but they're put in to increase combustion efficiency and reduce the amount of carbon MONoxide coming out the tailpipe. They also are added in much higher ratios (1 in 10 for gasohol).

Other disadvantages of ethanol are that it absorbs moisture, and it is not very soluble in gasoline. So, in the same way you see oil floating on water, the ethanol and gasoline in your gas tank stay as separate phases. Any water that gets absorbed into the ethanol phase can cause corrosion in the fuel system.



Also, as others have pointed out, ethanol has a lower fuel value than gasoline. Here's some math on the subject:

Gasoline is VERY roughly equal parts n-heptane, isooctane, cyclopentane, and ethyl benzene (see http://www.elmhurst.edu/~chm/vchembook/514gasoline.html). If we assume equal parts, the average of the heats of combustion of these four chemicals is about 4,600 kilojoules/mole. If you change the units around and convert mass to volume based on an average density of the four chemicals, you come out to very roughly 126,000 Btu/gallon, or 31,800 kilocalories/gallon.

Ethanol has a heat of combustion of 1,409 kilojoules/mole. Changed to similar units, that's 86,800 Btu/gallon or 21,900 kilocalories/gallon.

In short, you get about two-thirds the energy from burning ethanol than you do burning gasoline on a per-unit volume basis (21,900/31,800 = 0.688 ~ 0.667 = 2/3). So, in theory, if you burned pure gasoline and got 30 miles per gallon, you should get 20 miles per gallon if you burned pure ethanol. If you have a fuel mixture that is 90% gasoline and 10% ethanol, and say you have 10 gallons of this, you should expect to go 270 miles on the 9 gallons of gasoline (9 x 30), and 20 miles on the 1 gallon of ethanol for a total of 290 miles. You would have gone 300 miles had you had 10 gallons of pure gasoline, so your loss is 10/300, or 1/30, which is 3.3%.

The bottom line here is that using 10% ethanol in gasoline should reduce your mileage by about 3.5% give or take a tenth of a percent or two.


If you're burning E85, now you have 8.5 gallons of ethanol and 1.5 gallons of gasoline per 10 gallons of fuel. On those 10 gallons, you would expect to travel 45 miles on the gasoline (1.5 x 30) and 170 miles on the ethanol (8.5 x 20) for a total of 215 miles. That's a reduction of (300-215)/300 = 85/300, or 28.3%. The E85 you're buying had better be at least 28.3% cheaper than pure gasoline, or you're spending more to go the same distance with E85 as you would had you bought pure gasoline. By the same token, you would want your fuel tank to be 28.3% larger if you want the same cruising range.

None of these calculations change if your mileage differs from the assumed 30 mpg I used for the sake of the calculation. The difference is based on the difference in fuel value of ethanol versus gasoline, and that's constant.


Remember, also, that there are TWO reasons we want (or think we want) to use ethanol as a fuel. First, it's domestically-produced, so using it reduces our dependence on foreign oil (although I would like to see the economics of this fully worked out--what about the energy used to make the ethanol from corn or whatever in the first place? It can be quite substantial.)

Second, it's a source of oxygen, so using it, in theory, increases the efficiency of the combustion process and thereby produces less carbon monoxide and other noxious pollutants. That's why methyl tert-butylether (MTBE) was also used as an oxidant in some parts of the country until it was found to dissolve rubber fuel lines and gaskets and cause engine fires.


So ethanol overall is a mixed bag. It's domestically-produced and is cleaner burning. However, it is expensive to produce, diverts corn from use as a source of food, has a lower energy content, and can damage fuel systems over time in vehicles that weren't designed for it. Without government subsidies, it probably wouldn't be at all economically competitive with gasoline, at least at anywhere near current oil prices. One thing it is certainly not is a panacea.

RDG

A lot of good info here. I'm going to look at our gas stations around here to see if any have 100% gas for the old girl. This car has 97,000 + original miles on it and I have records that show that a new carb was installed at 87,569.4 miles. That is actually the last entry in a log that I found in the glove box. It looks like that was in the late 95 - early 96 time frame. I will have to ask what brought about that change. I did notice in the log that they were using regular and mid grade gas and the gas mileage varied from 8.1 mpg to 15.5 mpg.
Thanks again for all the great input.

OLD SKL 69

I wish I knew a place around me that had pure gas instead of the blend.

jaunty75

I think that in 99% of situations, 10% ethanol in gasoline can be used without a problem, even in older cars. As long as you burn through your gas fairly regularly, there isn't time for moisture to accumulate and do any damage. Heck, around here, Speedway (SuperAmerica) has been selling 10% ethanol gas for at least the last 15 years. I'll bet that most people filling up there never realize what they're putting in their tanks or don't care. I would bet that for most of us, it has become a fact of life without our even knowing it. It's not something to lose sleep over.

66ninetyeightls

Last time I was talking with the Shell Fuels representative at work he was telling me most brands in Ontario only put Ethanol in the regular grade gasoline and none in the premium. Since my car will always get premium I'm not concerned.

jaunty75

Interesting. But if a car was designed to run on regular, putting premium in just to avoid getting ethanol could do as much harm as the methanol would, maybe more.

66ninetyeightls

How do you figure that??? Yes its more money but will do absolutely no harm to an engine to run higher octane fuel than it was designed for.

66ninetyeightls

The octane rating of fuel is nothing more than the rating of the amount of energy required to start the chemical reaction in that fuel. Its only purpose is to prevent uncontrolled detonation due to excessive pressures in the combustion chamber.

The energy delivered to a standard spark plug gap is 12,000 - 25,000 volts and the average spark gap temperature at the point of ignition is 60,000 Kelvin. This is MORE than enough energy to ignite even the HIGHEST octane fuel available on the market. The fuel in no way shape or form requires high combustion pressures in order to burn properly.

This type of testing is actually part of my day to day job and I work very closely with all the major fuel companies making sure their fuel meets all the requirements of our engines.. The additives they are using in modern gasoline has changed dramatically over the last 20 years. Even over the last 5 years there has been a dramatic change in fuel composition especially when dealing with winter vs summer fuels.

There are many places in Europe and Asia where the lowest octane avail is far higher than our highest octane and they see no ill effects on their engines after hundreds of thousands of kilometres / miles.

Is it smart to run higher octane fuel in a car that doesn't require it. NOits foolish because you are spending extra money when its not required for normal operation.

Will running higher octane fuel cause any damage to engines with lower compression. NO

Is there a benefit??? POSSIBLY. That really depends on the brand of fuel. Many fuel companies put higher levels of detergent and anti corrosion chemicals in higher octane fuel in order to keep modern fuel injectors and pumps working properly. Although not really required for classic vehicles running carburetors it couldn't hurt.

Red Delta

I miss my propane powered 1980 GMC 3/4 ton. Nothing like the scent of rotten eggs in the morning.

toro68

I'm a member of SEMA too!

66ninetyeightls

I love propane. Nothing like doing an oil change after 5-8k and the oil coming out as gold as it went in

Olds64

Is ethanol blended gasoline cheaper in your part of the country? That is another thing to consider. In Oklahoma City there is a Love's gas station that sells ethanol blended gasoline for about $.20 cheaper than the Shell station across the street. It is amazing that the Shell station can stay in business!

jaunty75

That's huge. Around here, no difference in price. Stations that do have ethanol don't tout it. Stations that don't don't tout it. Regular gas is regular gas around here.

70 cutlass s

I have a funny store about this. I was at a gas station one day. There was another one right across the street. I stopped at the one that had the higher prices not for gas for a drink. A person was paying for gas talking about they would only that brand gas for there car. I pointed out the gas truck. That it went to both gas stations.

Olds64

That is interesting. I've heard gasoline in our country is all the same since there are only a handful of refineries. I guess the only difference is the stuff that is added (ie. ethanol, or other "patented additives").

66ninetyeightls

Yeah that is true in my neck of the woods anyway. The major companies can't afford to have their own refinery in every area/market so they each go to eachother refineries. enter a code at the filling station and the fuel is mixed on the spot with their own additives.

Ethanol fuel should technically be more money because its more expensive to make ethanol. The difference in gas price is most likely due to the fact it sounds like a private station rather than a franchise.

RDG

The price of gas around here only varies by a few cents. Haven't had a chance to cruise around and check how many are selling ethanol enhanced or is that detracted gas. I pretty much buy at the same place just for convenience (connected to the grocery store - where I buy my beer) but it is almost always the cheapest around.

Ramjet

Ethanol is bad news for those of us especially who have carburetors.
The ethanol will eventually attack your rubber components. IF your accelerator pump cup is the black rubber, it will not last a month without failing with todays ethanol gas.
If the cup is blue, it is designed to be "alcohol resistant".
Leather pump cups live pretty well, but will dry out and become inoperable.
The ethanol in the gasoline also leans out the air-fuel mixture and has created lots of problems with stationary engines, small engines, etc. and will give our cars driveability problems.
If you can stay away from ethanol, your carbureted car is better off.
We even see fuel economy losses with current day autos.
Ramjet

Olds64

70 cutlass s

My brother in law and I where talking about this about a year ago. We both have noticed the same thing. We had similar cars that got about 5 miles less to the gallon than they did when we first got them. Both cars in good running condition, but both had similar fuel economy loss and the only thing we think of was the ethanol gas blend.

OLD SKL 69

That's great right? So we dilute the gas so it is less efficient and then we need more of it to go the same distance?

wjustinmartin

Is there a website where non-ethanol gas stations/retailers can be found?

jaunty75

Cutlass S's comment above about the loss of 5 mpg in using the 10% ethanol gas is a bit unbelievable as ethanol doesn't reduce the energy capacity of gasoline by that much. At least, he should tell us what his overall mpg is so we can put that 5 mpg loss in context. Is he dropping, for example, from 35 to 30 mpg (which would be a 14% loss) or 15 to 10 (a 33% loss)?

Given the energy density difference between gasoline and ethanol, you should expect maybe a 3-4% loss in mpg. On a car that gets 25 mpg with pure gasoline, using gasohol should drop you to just over 24 mpg. A loss to be sure, but not a large one.

Your comment above misses the point about using ethanol in gasoline. It is recognized that there will be a small loss in mpg, but by putting a little ethanol in gasoline, the completeness of the combustion is improved (ethanol adds an oxygen source to the fuel in addition to air), so the amount of pollutants coming out of the tailpipe is reduced. It's a trade-off. A little poorer mileage in exchange for a little cleaner air. That's the theory, at least. Another advantage, in theory, is that ethanol is home-grown. A little poorer mileage in exchange for fewer U.S. dollars going to Saudi Arabia.

It all depends on how you look at it. The effect of ethanol on mileage is only one of several considerations that go into the decision to put it in gasoline.

70 cutlass s

My good friend Jaunty good morning. Well yes there is a little more to it. Both car where 15 years old so some of issue of fuel mileage loss had to do with the car. Having 200,000 on them not all on the gas. The cars 1994 Olds and Pontiac with 3800 engine. Both got around 30 mpg when newer. Last year mine would around 26-27 mpg. No its not 5 mile drop I just rounded up the number. My brother in law his fuel mileage suffered more then mine because of a transmission issue.

jaunty75

So you're not telling us anywhere near the whole story! Your situation makes a little more sense when seen in the context of 200,000 mile, 15-year-old cars, one of which has a bad transmission. And then you're rounding a 3 mpg loss to 5 mpg. I guess I could make changing the flat tire I got last night into an epic journey through the three stages of hell accompanied by a battle for survival if I tell it right, couldn't I?