10% Ethanol vs. Ethanol Free Gas
 

Please offer your opinion on this topic. I know there's been some Ethanol discussions on the forum, nevertheless, not specifically what I'm asking. So anyone with a very good understanding of Ethanol's characteristics and how it effects the car ability to perform at peak performance and overall internal functions long term, please chime in. Thanks in advance!

Okay ... taking into consideration PERFORMANCE and WHAT'S BETTER FOR OUR 370Z OVERALL. The latter being very important.

Deciding Facts below:

1. I have a local Exxon/Mobil Gas Station that offers 90 OCTANE ETHANOL FREE GAS AT A PREMIUM OF $4.05.
2. Compared to a local Sunoco Gas Station that offers 93 OCTANE WITH 10% ETHANOL FOR A PRICE OF $3.65.

My question: Is it better to run 90 Octane Ethanol free gas vs. 93 Octane w/ 10% Ethanol?

Here in Canada, we don't have a choice. All gasolines have at least 10% ethanol. Some have 15 to 20 percent.

If you had a choice, what would it be? Inquiring minds would like to know.

Regards,

Stino

I would like the ethanol in. Although I would like it only around 5%. Gas with ethanol works better up in these climes.

Rarely you will find a gas station that doesn't sell gas with 10% ethanol.

As a petroleum engineer, I HATE ethanol. That being said, I'm having a tough time choosing between the two for you, but I would probably go with the 93.

I too have an inquisitive mind and would like to learn a little more about the role ethanol plays in the fuel we put in our cars. Can you elaborate for us please :hello:

I'm no Chemist or expert of any kind really, but I've been using ethanol "enhanced" gas since the 1970s (not all the time, mind ya) in various vehicles and my observations are:

For real old cars (before the Gas Crunch of the mid-'70s), ethanol could attack the gaskets in the carburetor, the fuel pump diaphragm, &c. Not all cars, but it wasn't all that rare. Seems that the older the car, the worse things got.

For cars between then and the introduction of ECUs (ECM in Z-talk) the engines seemed to "tolerate" fairly large amounts of ethanol. The better the electronics they had, the better job they could do, but not quite there.

For most modern cars, 10% is no problem. I've had to put 10% in my '09 and haven't noticed any ill effects.

HOWEVER
Ethanol has fewer BTU per gallon - ~114,000 for regular unleaded vs ~82,000 for E85 (couldn't find a value for E90, but you get the picture). You have to burn more fuel to get anywhere. I haven't noticed much of a difference in power with my butt dyno, but haven't really made any comparisons - I seldom use full power and when I do, I've always gotten enough to make me grin.
Ethanol and water love each other. Especially in higher concentrations, it can pick up water (and some of the crud it has with it) and carry it to the pump, filter, injectors, &c. For a newer car that hasn't had time to collect condensation, this is seldom a problem, since most gas has a little ethanol in it anyway and the water gets carried out in tiny amounts.

All that said, I try to get 93 octane sans the ethanol, but I don't get obsessive about it. If I get anything below 93, I try to keep my toenails out of the radiator until the next fillup. I had to buy 90 octane once - just got enough to baby it home and then filled it up with the good stuff. I try to avoid anything above 10%, just on general principles, but finding 0-10% hasn't been a problem so far.

Keep in mind that all of that is just my personal observations. Nothing scientific about it (except for the BTU/gal figures and I rounded them).

@redline727, it seems SouthArk370Z knows more about the effect ethanol has in a car in a mechanical aspect than I do. My personal hatred for ethonal and it's supporters is that it takes MORE energy and resources to harvest ethonal than the amount of energy and resources ethanol can produce (and the harvesting of it uses coal electricity and a ton of fossil fuels, so don't think it's better for the environment). It's like cutting meth (I've been watching a lot of Breaking Bad) with a substance more expensive than meth, with the belief that it will save you some money (although it is a lot more political than that). Anyone who is ordering the manufacturing of ethanol is either dumb, an idealist, or holds a private agenda.
Hope that helps!

I would choose 93

It really depends if the 90 octane will cause any retard in the spark timing. If it does, then it's a no brainier to run the 93. Regardless. It's not worth much of a premium over e10 just in terms of energy content.

Thanks to everyone who responded to my question. I'll continue using the 93 octane. Thanks again!:tiphat:

Regards,

Stino

Not the case over here in Ontario, we get 91 octane ethanol free from Shell.

That's all I have ever used in my 370z, my Z32 was tuned for 94 octane so that's all I used in it.

I also remember reading articles talking about ethanol fuel lowering gas mileage, very little amount but still less.

Go with the octane for the car. The reason we have 10% here in the US is the gov and the ridiculous corn subsidies the american public was duped into paying for all these years.

Its cost the citizens billions and we continue to slurp it up because we have to.

10% fuel sucks for anyone with a carb (many motorcycles, small equipment) as it does gum up the carbs when sitting. They didn't seem to mention that nor consider it when they moved to have us all use 10% did they?

I have *one* station within 100 miles here in eastern PA that sells ethanol free 87 and 100 race fuel..so at least now I can get some 87 for the motorcycle, lawnmower etc...

- b

There is a station less than half a mile from my house that sells non-ethanol "marine" gas. Since it is only 87, none goes in the Z. However, it has been great for my lawn equipment, and before my old 65 Chevy pickup died, I used the non-ethanol in it too. If there was an option for "premium" grade non-ethanol, I would probably run it in the Z too.

I see your spreading misinformation again.

Check your facts before spouting information that is not true :tiphat:

Shell 91 Octane has NO Ethanol in the premium blend and has no plans to change that in the near future. However a 94 Octane, ethanol blended premium fuel, may be in the future :tup:

It could be a answer to Petro-Can's Super 94. To date, I haven't found out much Ethanol is in PC's Super 94, but the search continues.

My little research showed that 5% ethanol gave 5% less gas mileage and 10% was 10% less mileage.

Worked out to 2.5 mpg on the Challenger on 91 octane fuel with 10% ethanol. Same price as Shell 91 and 10% better gas mileage........ no brainer for me which fuel to buy.

What I've noticed is I get better gas milage with 76' 91 than shell vpower... me thinks one waters down their brew a bit less...

:tup: glad to hear shell doesn't want to change it to!


That's a crazy difference for gas mileage! :iagree: though, it is a no brainer which gas to use in the Z! Since day one with my 40th(bought new 000015km on delivery F.O.B.!) it has only seen Shell 91 ethanol free gas I bet if I looked at all my receipts 90-95% of the time it was filed at the same shell :rofl2:

as do i. i get consistently better gas mileage with 76's 91 octane over shell's 91 octane. about 2-3mpg each tank.

ditto SouthArk
 

Not an expert on gasoline nor a mechanic or even a Z owner yet (ordered), but what I learned about gasoline as an amateur recreational pilot agrees with Southark's post earlier. The alcohol increases the anti-knock index and therefore the octane rating of the gasoline but decreases the energy and increases problems with water.

The main problems in aviation are the lower energy content, the effect of alcohol on gaskets, seals and fuel lines not designed for it, and the attraction that alcohol and water have for each other. Many airplane engines are high compression engines that require higher octane ratings to avoid detonation and pre-ignition in high power operations (as in take off when the trees at the end of the runway can get close really fast). Takeoffs in small airplanes are full throttle maximal performance operations. Every bit of rated power is demanded so the lower power production of ethanol is a safety issue. Detonation can destroy the engine. It is also more likely when the engine is hot and the recommended action is to cool the engine by increasing speed (they are air-cooled) and reducing throttle. Avgas still contains lead as the anti-knock agent. Small airplanes sometimes sit for weeks unused. The air in the unfilled space in the tank contains moisture that may condense into the fuel on cool nights. Over time this can put enough water in the gas that it can cause problems--like engine failure and crash on takeoff. If the gas contains alcohol, the water can combine with the alcohol causing it to separate from the gasoline and create a large layer of water-alcohol sitting at the bottom of the tank.

Having said all that it just makes sense to me to prefer alcohol free fuel if it is available at the octane rating that the manufacturer recommends for any engine, especially if the fuel will sit there for a long time. More so in winter. The condensation problem can be countered by keeping the tank full instead of nearly empty. The less air space in the tank, the less water vapor will be available to condense each night. I gather that some Z owners use their cars only recreationally rather than daily drivers. It also makes sense to, if one must run fuel of a lower than recommended octane rating, to keep rpms and engine temps down and, if you value your engine, to not forge ahead if you think you hear knocking.

I have one vehicle that can sit for weeks unused. After some fuel problems, I began toping it off with ethanol free fuel before leaving it to sit. But the fuel is of the recommended octane rating so I am not compromising in that regard.

Not the place to rant about the ethanol racket but if one adds the information about reduced gas milage to the available data about fossil fuel requirements to produce ethanol, it is sort of obvious to any who care to look. Nuf said.

I like your comment and would say :iagree:

I'd go with the cheaper Florida Law prohibits the sale of Ethanol Free in cars. For off road use its legal and should be cheaper since you shouldn't be paying road tax on it. They are probably doing what diesel pickup drivers do, buy home heating oil and run off of that and avoid the DOT tax and making a killing in profit. Or they are flat out lies.

"Florida RFS (Renewable Fuel standard, March 2008) required MANDATORY 100% blending of ethanol for public supply of gas by 12/31/2010. Exemptions exist for fuel used in aircraft, boats and watercraft, fuel sold to a blender, or used in collector vehicles, off-road vehicles, motorcycles, and small engines. View Press Release and House Bill 7135, section 103 of the Florida Statutes.

Florida law requires gas pump labeling with an E10 sticker when ethanol is added to gasoline. Sadly, several stations that advertise E0 ethanol-free gas, actually are selling E10! Many that sell E0 inflate price per gallon by far more than it costs them."
Florida - Florida - Ethanol Renewable Fuel Standards & E10 Laws

Just thought I would chime in. I have been using 92 octang ethanol free gas for over 2 years. My Z got from 1 to 3 extra mpg without the ethanol. Also ethanol-free gas stores better as well. This is important for my emergency generator and lawn tractor. I am a total convert to non-ethanol gas. I have had no problem with water in my gas line or tank, btw.

I'm all for ethanol free gas, it's so much better, there was a reason gas suppliers didn't put it in themselves till the government (tax payers) subsidized it and states required it. It's more expensive, needs more of it to go the same distance, absorbs water, and breaks down rubber parts. Unfortunately it doesn't exist in the NY/NJ area.