FirstC4

I know that storing over the winter with ethanol-free gas is best.

No evelation here in the flat Midwest. Just curious if using a 2 octane point less, but pure gas is actually better to run, or no difference with a stock car?

91 octane pure gas/ ethanol free vs. 93 octane w/ 10% ethanol

JR-01

When I switched to ethanol free gas my gas gauge started acting up again. Now I stick with Shell 91 octane V-Power with up to 10% ethanol. I will add a stabilizer over the winter. It's hard to say which is best, but that is what works best for me.

Vetteman Jack

Hard to say anymore - we don't have any non-ethanol gas around here that I know of. I haven't had any problems using the 10% ethanol stuff in my car.

Cybermind

Same here. No ethanol free gas in my area. I always use 94 octane (10% ethanol) and have never had any issues. It's Petro Canada gas with some sort of cleaning agent which I don't recall the name. I do add stabil in the gas tank every winter.

ssrallyred

I live in Destin Fl and we have a Chevron station and it has a pump with 93 octane with no ethanol. Its there for all the boats around the Emerald Coast but a lot of car guys fill up there lol.

Phanni

I use 10% in all my cars, but I opt for ethanol free for all my power yard machines, boats etc.

v98roadie

What's the real question? What's better for engine life or better for engine performance? E10 (ethanol is an oxygenated fuel) can increase performance and will decrease MPG while ethanol free gas will get better fuel economy. What do the fastest race cars on the planet run? Oxygenated fuel (nitromethane) and it works real well for about a quarter of a mile! Ethanol free gas causes less wear and tear on the engine's internal parts especially cars built prior to 2001. Most cars built after 2001 were designed to run E10 though I would use an additive like Techron if it were me. For top performance run E10 for top fuel economy and long term durability run ethanol free. I'm not a scientist nor an engineer but I have spent a great deal of time studying fuel types, BTU content, fuel performance and fuel economy for my business. This information is readily available from many reliable sources.

calvins

I thought ethanol was nothing more than moonshine. Didn't know it had anything to do with O2

JR-01

E85 has 100 to 105 octane. Could that be used in high compression engines without modifications? Or would it destroy them?

JR-01

......

v98roadie

Man I'm not qualified to answer that. I know top fuelies have something like 6.5:1 compression. It probably depends on how far you wanna go, it might make a quarter mile real quick!�

calvins

When you's right, you's right. I mean everyone knows that increasing O2 to the mix gives better results. I just never knew that ethanol did that before.

http://www.afdc.energy.gov/fuels/eth...el_basics.html

Lazarus Long

I get ethanol free when I can get it. Ethanol attracks water and can turn into sludge. Ask a boat owner about the evils of ethanol. It has been one of the better con jobs foisted on us and is just a payoff to the farmers.

JR-01

Actually ethanol and water mix, eliminating gas line freeze and water in the gas. However, it does degrade faster than gas which causes problems in engines that sit for long periods like boats and lawnmowers. There are hundreds of millions of cars using ethanol everyday with no problems. It's not the farmers that made a killing on ethanol, it was Archer Daniels Midland.

CaliforniaJack

Ethanol is an Alcohol. It will burn much more easily than a hydrocarbon. That makes it much more resistant to knock if your engine has a 14:1 or higher compression ratio. Ethanol has much less energy than the same amount of a hydrocarbon like gasoline, which is compensated for by using much more Ethanol to produce equivalent power. Ethanol was a government sponsored attempt to reduce the consumption/cost of foreign oil which has now dropped by half. No normal corvette engine can benefit from the addition of Ethanol. PS. Yes, I'm a Chemical Engineer.

duramaxsky

wysokowski

So the fact that ethanol keeps the fuel system cleaner and eliminates water issues is not a benefit?

MrMcE

I've read ethanol is bad because it eats rubber or plastic. Where it would touch rubber or plastic, idk really.

The gas station I go to calls 91 their best premium and it's ethanol free. Significant markup in price, though, but I'm not putting too many miles on. I wouldn't pay more for 93, the ethanol presence wouldn't change my mind.

MWWarlord

Where I am the 91 ethanol free actually costs more than the E10 93. My supercharged car is tuned to run on 93 octane, so that is what I run. There are pretty regular threads about octane rating . The bottom line is that it all depends on how your car is tuned. A stock C5 can run just fine on 91 octane, but you will lose bit of power in doing so.

jackthelad

10% Methanol was put in to replace MTBE, which started to be added to gas in the 1980's. It does basically the same thing - adds Oxygen, increases octane and reduces emissions. MTBE was replaced because if it gets in the ground water, it spreads and will pollute wells. The only non ethanol gas I have seen around in this area has been so-called racing gas at about 2x the price of the normal stuff. Our cars are factory tuned to run 91 and up octane. To take advantage of anything above that, an aftermarket tune is needed. As to choosing between "pure" and ethanol, as long as the pure has a proper additive package, it will be fine. No better. no worse - unlesss it does not have the additive package, in which case don't use it. The additives are there to reduce wear among other things. I stick with "Top Tier" gas (basically the big brands plus some others, Costco for one) where possible, which guarantees a decent additive package, though I am not fussy about it. Sometimes the cars get filled with the cheap stuff from the supermarket.

Incidentally I have never bothered to drain gas or use stabil over winter with either our cars or small engines and have never had a problem as a result. Winters here are not that cold though, only around 10°F, +/-.