Recently a new gas station opened in my town offering ethanol free gas at a premium price. Currently the E-10 stuff is priced at $2.69 gal, while the pure gas is $3.29 gal.

Yes, I might get a little bit better mileage and performance with pure gasoline, but to my thinking it's not enough to offset the cost of buying non-ethanol gas. I'm finding it hard to justify paying 60 cents more per gallon to get maybe a 3% increase in mileage.

From what I've read, if you have a modern fuel injected car, it's going to run fine on either, as it was designed to do that. So in that case it becomes just like the long dismissed argument "I use premium gas instead of the regular it's designed to run on because my baby is worth it."

But where there might be potential long term issue is with older carbuerator equipped vehicles, including older lawn mowers, engines not designed to run with that ethanol mix. The Ethanol additive is water based and I understand the theory is it might allow moisture into areas it doesn't belong perhaps resulting in premature corrosion.

A chemist is in a better position to discuss this than me.

I know the 94 Q45 experienced issues as the ethanol additive increased. I'm in hopes the 2015 engines are more ethanol tolerant.

I run the ethanol free in my mower, motorcycles, and if I can find premium Ethanol free, in my Z. Everything else gets standard.

Ethanol got a lot of hate when it first came out... mostly for the reasons Joel mentioned... it ended up soaking up a bunch of the water that people already had in their fuel systems and caused some issues, along with slightly changing the air fuel ratio on vehicles that don't have a closed loop feedback system (O2 sensor, fuel injection).

Ethanol gas now in modern cars is actually better for everyday use than the old stuff. Ethanol does a HELL of a job keeping stuff clean, and keeping that water out of your fuel system/keep it from building up (its essentially what the old bottles of gas line antifreeze were... either that or methanol in the "HEET" version). For non-direct injected cars, it'll keep your intake valves cleaner in the long run. It also reduces combustion chamber and EGT temps when you're beating the snot out of your vehicles.
Honestly I wish more stuff was tuned/built to run on E85, cos I'd totally do it. I used to run a tank or 2 through my Miata and truck every now and then (and tune the ECU accordingly) just to clean stuff out.

Ethanol has lower energy content per volume than gasoline, but the factors Smurf outlined tend to compensate for that. It is a mild octane booster as well.

I've never owned a car new enough to be built with E10+ in mind, but modern stuff is sort of designed around it. Even my freaking Honda-powered lawnmower is ethanolized fuel friendly, and it's got a carburetor.

In the LS8, my unscientific observations show a ~3mpg increase with ethanol-free 91-octane (at relatively high altitudes) vs ethanolized 91 at the same altitudes. These observations were made over a long-distance highway route I travelled tens of dozens of times, and certainly include unaccounted factors. But the LS8's fuel economy is SO consistent with my driving habits that even a 1MPG difference between tanks is pretty unusual unless one tank is 100% highway and the next is 100% city driving.
However, the LS8 also tends to run hot, especially cylinder head temps, so I've always wondered if the side-effects of ethanol in fuel might be beneficial there (increasing octane, lowering combustion temps).

3mpg is a pretty decent percentage gain... over 10%, however still doesn't justify the 22% cost increase that was outlined in the original post.

And I was fairly certain there was talk of ethanol blend pretty early, as well as studies done to make sure most modern cars (with closed loop feedback) would be ok to run on ethanol. From what I understand, the studies showed that there was no major issues using E10, but they started to see some with E15. Everything built Model Year 2001 and newer is meant to withstand E15.

Bubba1 wrote: ↑

Sat Jun 02, 2018 12:59 pm

From what I've read, if you have a modern fuel injected car, it's going to run fine on either, as it was designed to do that.

But where there might be potential long term issue is with older carbuerator equipped vehicles, including older lawn mowers, engines not designed to run with that ethanol mix. The Ethanol additive is water based and I understand the theory is it might allow moisture into areas it doesn't belong perhaps resulting in premature corrosion.

From personal experience, My snowblower is meant to run on non ethanol gas.
It even says in the owners manual not to rum e10, and it's only 3 years old.
I ran it once with regular gas, 10% ethanol, by mistake, and it ran like crap.
I drained the tank and filled it up with ethanol free premium gas. Huge difference.
As for my car(s), they run fine on just about any grade of gas, with no real noticeable difference.