Ethanol? or no ethanol?

[92EagleAWD]

I found a local station hidden away here that sells 90 octane gas with Zero ethanol. I want to know if 90 octane with Zero Ethanol is better than 93 Octane with 10% ethanol? Or if there is any difference at all.

 

[GRAVEDIGGER]

You need to run high octane (93), so stay with that. The 90 octane is still 90 octane and will knock before 93 octane will knock. In fact, ethanol is an octane booster and is found in most higher octane fuels, so it's a good thing to have for our cars. So, stay away from the 90 octane without ethanol... Your car won't like it.

On a side note the 90 without ethanol would most likely yield better cold starting and slightly better mileage on a low compression naturally aspirated engine though. But, anything turbo or high compression would not be advisable to use with it.

 

[gusu]

The only negative effect of ethanol is lower gas mileage but since its only 10% ethanol you should only see about a 3% loss in fuel economy.

Don't buy into the "ethanol ruins rubber seals and your piston rings". Its true... if you car was made in sometime in the 70s or later. HOWEVER cheap crap fuel pumps or buying the cheapest lines you can fine most likely are NOT protected from corrosion from ethanol. I wouldn't worry about this too much, if you go in and buy a fuel line its almost always going to be treated, the problem comes when you walk into a place like Home Depot to buy replacement hosing.

 

[4g63Powered]

General rules of thumb:

1.) Keep to 91+ octane whenever possible.
2.) 10% ethanol is basically ubiquitous.

Buy the 93. Your engine will thank you.

 

[TerryFick84]

I put some 91 non-ethanol in my car and the power seems better and i was able to hold 2 to 3 more pounds of boost without knock

 

[92EagleAWD]

I put some 91 non-ethanol in my car and the power seems better and i was able to hold 2 to 3 more pounds of boost without knock

See, this is what i was referring too. I have heard of SOME instances that the non-ethanol gas yields better performance with less knock. I just wanted to know if someone could show some hard proof. Maybe a log of 2 runs with and without ethanol or something like that?

 

[Imback]

Only real way is to try it your self. Every car reacts different.

 

[standard235]

Ethanol is knock resistant in itself due to the cooling effects of alcohols (ethanol included).

Look at the success of e85, tune for tune, e85 makes more power per lb/min of airflow.

 

[DSM1G90]

The whole power thing with fuels is relate to how much BTU output per measure of fuel burnt - how hard the exploded fuel is pushing the piston down.

Actually, that 10% raises the octane level close to 2 ticks, but lowers BTU output.

E-85 is like running 110 octane (good to quell the knock syndrome), but BTU output is much lower than the E-10 fuel mix.

And, it's more expensive with that extra 10% per gallon than the non E-10 stuff since it costs to make the ethanol and that cost is passed down to the consumer ... and with gas prices starting to go crazy ......

And non E-10, 91/93 would render more power since there is more BTU output, is why the one user is making the comment below on this fact:

I put some 91 non-ethanol in my car and the power seems better and i was able to hold 2 to 3 more pounds of boost without knock

Just that non E-10 pumps are hard to find in some states ...

-DSM