Pure Gasoline vs 10% Ethanol in older vehicles

[JasonTL]

I've been wondering what the performance difference is with Pure Gasoline(undiluted non-ethanol) versus 10% Ethanol or 'Standard' gasoline, namely in older cars. I have an 88' Suburban and can get pure gasoline for ~11% more than normal gas. I'm wondering: Is the pure better than the ethanol for my vehicle due to its age, or will it not make any difference? Would power be affected? How would MPG be affected? Would the pure gas be better for seals and other components, or is there no change? Does one type keep better over longer periods of time? Both 'Pure' and 'Standard' in this discussion are of 87 octane. Thanks.

 

[raytseng]

Was has the car already been running on E10 for some time or not? If it's already had it for some time, then that's the answer. Power maybe affected since ethanol has less energy; however it will be less than 10%. If it affected it by 10%, it would be like the ethanol had 0 energy. Your MPG may also be affected, but should be less than the 10% as well. Depends on how it ends up affecting your driving habits From a pure price perspective, the 11% extra you pay means the ethanol is actually decreasing the energy of the pure gas by 1%.

 

[Chris142]

fuel injected cars can compensate. i always had problems with ethanol gas on cars with carburetors

 

[Eddie]

10% ethanol in your fuel results in a heat reduction of 4.3% so one expectsa a 4.3% loss in mileage. There may be other factors involved such as carburator settings etc. A fuel injected engine my overcome a small portion of the loss. Ed

 

[SteveSRT8]

Ethanol proponents are fond of quoting math stats. Real world stats from my fleet are one car gets WORSE than 10% drop in mileage with E10. Fleet trucks seem to be a bit better, but absolutely nothing in a huge driveway and lot here gets a 4.3% hit. Dream on. Note that every vehicle is later model fuel injected V8. I have others that we don't track fuel consumption on. All of them seem to like it just fine, never had an issue with quality, but mileage is not as good as supposed above IME...

 

[bepperb]

It's been mandatory in SE Wisconsin since 1996. I've never had any problems with it damaging things. I don't notice a big fuel economy difference, but I don't pay close attention and the only time I get 100% gas is on long highway trips. Still, I do believe regular gas stores better. But a 1988 car should handle E10 just fine.

 

[edhackett]

Originally Posted By: SteveSRT8

Ethanol proponents are fond of quoting math stats. Real world stats from my fleet are one car gets WORSE than 10% drop in mileage with E10. Fleet trucks seem to be a bit better, but absolutely nothing in a huge driveway and lot here gets a 4.3% hit. Dream on. Note that every vehicle is later model fuel injected V8. I have others that we don't track fuel consumption on. All of them seem to like it just fine, never had an issue with quality, but mileage is not as good as supposed above IME...

All ECM tuning and emission certification is done on ethanol free fuel. The car cannot tell oxygen from the air from oxygen carried by the fuel. The ECM enriches the mixture in response to the increased oxygen in the exhaust due to the ethanol. That's why fuel mileage is often greater than chemical theory would predict. Why not compensate the programming for E10 with an offset? It's a delicate balance to meet NOX with a three way catalyst. A bit too rich favors NOX reduction both in the engine and the catalyst. The higher HC is easily handled by HC oxidation of the catalyst. Leaner(no ethanol) increases NOX, which is not handled as well by the catalyst under those conditions. Compensation could be done if there was a sensor used that was capable of reading the ethanol content accurate to 1% ethanol. Ethanol has zero net effect on emissions in a modern car operating in closed loop. The reduced emissions are offset by the greater amount of fuel burned. Ed

 

[y_p_w]

Just curious why anyone would call gasoline "pure". There's nothing pure about modern gasoline sold at the pump. It's not absolutely 100% hydrocarbons. There's lots of non-hydrocarbon impurities whose concentration is more a matter of how much it costs to remove them. Then various additives are used - some of which don't really improve the performance such as dyes. The anti-corrosion, detergent, stability, and other assorted additives serve a certain purpose but don't necessarily improve energy content. It sounds like a lousy way to attempt to describe gasoline that doesn't have oxygenates added.

 

[Spector]

Do not have an older vehicle but I have been running 100% gas for the past 9 months or so and it costs 20-30cents a gal more. However, the increase in MPG is very noticeable on my little 4 cyl econobox and even more noticeable in my hybrid. IMO more then makes up for the price differential.

 

[SteveSRT8]

Originally Posted By: edhackett

Ethanol has zero net effect on emissions in a modern car operating in closed loop. The reduced emissions are offset by the greater amount of fuel burned. Ed

I appreciate your time to type out that explanation, but I get that part. Most of our fleet trucks are now flex fuel models, so they do compensate nicely even for small variations in the amount of ethanol. I disagree with the emissions statement, as a great deal of research on the net indicates that many undesirable by products are emitted, especially the ones with 'zene' on the end...

 

[edhackett]

Originally Posted By: SteveSRT8

[ I disagree with the emissions statement, as a great deal of research on the net indicates that many undesirable by products are emitted, especially the ones with 'zene' on the end...

I was speaking of the gross emissions that ethanol is added to reduce, primarily CO and HC. I'm well aware of the increase in air toxics due to the combustion products of ethanol. Ed

 

[hatt]

For 11% more I wouldn't run anything other than E0. Only you can figure out if it make financial sense. If it's driven regularly I doubt E10 would be doing any damage. If you don't drive it often the E0 is a no brainer.

 

[TiredTrucker]

As for the emissions stuff, there is no "clean" fuel available. Ethanol has its issues, most times, folks zero in on various aldehyde formations, but gasoline has a laundry list of known carcinogens that get emitted. And the concentrations make a difference as to whether a particular component is really all that dangerous. To the original question, if a substantially older vehicle has not ever used E10, and one still has straight gas available, it might be a good thing to just keep on using straight gas if it is available. The ethanol will loosen up any buildup in the fuel system and could cause a few frequent filter changes or something a little more difficult. A '88 vehicle would have no problem if it had E10 frequently since it's build. I ran vehicles just fine in the late 70's / early 80's on E10 without ever seeing any issues. And many of my neighbors, the same. Energy level of the fuel does not necessarily equate to lower fuel economy. To be fair, ethanol will show some mpg loss in most gasoline engines, primarily because their timing, compression, and other characteristics are set for gasoline and not for ethanol. There are several engines in development now, that have power outputs comparable to diesels, especially torque levels of diesels at lower RPM's than most production gas engines. at half the displacement of diesels, with mpg numbers a little higher than gasoline. And they do it on E85. There are many characteristics that make ethanol, especially E85 at the pump, a better fuel from a working or high performance engine, that gasoline at the pump can't even come close to matching. But to garner the benefits, the engine has to be designed primarily for it. On E85, it is proven that the proper engine design, a 2.8L E85 engine can produce more torque than most NA 5L-6L gas engines, and they can reach 90% of available torque at around 1800 RPM and peak at only 2800 RPM, and hold peak torque longer on up the RPM band. Most V8 gas engines don't even reach peak torque till way on up the RPM band, most not till they get around 4000 RPM or more.

 

[Garak]

Typically, where one sees benefits with E10, it's with older vehicles with rudimentary emissions systems. For various reasons, I've used a lot of E10 over the years, including long before anyone thought of mandating it.

 

[SteveSRT8]

Peak torque at 4k? Who cares about peak, it's all about available. My car has a big cam and still has over 300 foot pounds at 2k, and that's plenty. Our vans are similar. Heck, Overkill's M5 has a torque curve as flat as can be. Table flat torque curves are very common in stock V8 engines. It's one of their most endearing attributes. So is longevity, which is yet to be as proven with these super complex boosted motors...

 

[oilotaku]

we run 10% in our 81 ford f150 and have done so for a few years now no problem we could seek out the few places in our area that have pure gas but they charge more

 

[CharBaby]

I have been running my '80 Firebird FORMULA V8-4bbl(purchased brand new) on 10% ethanol gas since it's arrived in my area. And, believe it or not, this engine runs better over the years than it did from new. I don't give 100% of the credit to ethanol but, I am almost afraid to try the Pure Gasoline available in my area. I credit most of the smoothness and better running in this engine to better tune-up parts that I changed to in about 1996-97. Better plugs, wires, cap/rotor and a timing & carb tweeks. Along with a regular dose of Sta-Bil and MMO in each tank of gas(probably for lubricity). IDK exactly when ethanol came about in my area but, I haven't noticed any detrimental effects to this carb or engine. Everything being original and unrebuilt ATMOF, this engine starts as good or better than when new. AND, after winter storage, which can last as long as 8 months without any starting...she starts(after several pumps of the accelerator pedal) without any knocking or other noises. Just nice engine purr in high idle til warmed up. I also haven't notice any detrimental effects of ethanol, with any of my OPE(lawnmower, snowblower, weed eater, leaf blower) that I can put my finger on. I am not PRO ethanol but, I don't see any issues with it in my personal vehicles or equipment and most of my stuff is OLD!

 

[TiredTrucker]

I will caveat the ethanol thing somewhat. There has become a practice with the oil companies, to dump sub par 83-84 octane gas on the market, blend it with 10% ethanol to get the octane up to 87 and sell it at the pump. I would be willing to bet that most issues with E10 could be attributed to that. In my area, they have the 87 E10, but they also have a mid grade 89-91 octane E10. Now that stuff is the true 87 octane gas blended with 10% ethanol, and I use it when the price favors it over E85. Same price in my area for the 91 octane E10 as the regular no ethanol 87 stuff. Seems a lot of folk's outrage might be a little misplaced regarding ethanol issues. Could it be the gas component that is the problem? http://ethanolproducer.com/articles/1023...e-on-the-market

 

[Garak]

That's where I've been annoyed with the ethanol mandate. I was buy E10 midgrade (at regular prices) for years, without needing anyone forcing me to do it. Now, thanks to this province's mandate, the regular is also E10, and the midgrade deal disappeared.

 

[y_p_w]

Originally Posted By: TiredTrucker

I will caveat the ethanol thing somewhat. There has become a practice with the oil companies, to dump sub par 83-84 octane gas on the market, blend it with 10% ethanol to get the octane up to 87 and sell it at the pump. I would be willing to bet that most issues with E10 could be attributed to that. In my area, they have the 87 E10, but they also have a mid grade 89-91 octane E10. Now that stuff is the true 87 octane gas blended with 10% ethanol, and I use it when the price favors it over E85. Same price in my area for the 91 octane E10 as the regular no ethanol 87 stuff. Seems a lot of folk's outrage might be a little misplaced regarding ethanol issues. Could it be the gas component that is the problem? http://ethanolproducer.com/articles/1023...e-on-the-market

There's nothing unusual or wrong about that. The idea is the finished octane rating of the fuel. In today's market there's already a hard enough time getting enough blend stocks for all the 91 octane vehicles. Ethanol actually helps to meet demand for higher octane finished fuel. They have to be blended at the terminal with ethanol to achieve the desired 87 octane rating. Why would a business buy 87 octane fuel, blend it with 10% ethanol, and sell it at the pump as 87 octane fuel? The fuel available for sale in some areas in the Northeast is called "Reformulated Blendstock for Oxygenate Blending". http://www.eia.gov/dnav/pet/tbldefs/pet_move_wkly_tbldef2.asp

Quote:

http://commodities.about.com/od/profilesofcommodities/p/gas_futures.htm RBOB Gasoline Futures - Fundamentals : Reformulated Gasoline Blendstock for Oxygen Blending (RBOB) Futures is the new name for unleaded gas futures. The NYMEX has changed the grade of gasoline that is to be traded at their exchange in 2006. RBOB is a wholesale non-oxygentated blendstock traded in the New York Harbor barge market that is ready for the addition of 10% ethanol at the truck rack.