cb98coupe

There is a gas station relatively close to my house that offers 90 octane ethanol free gas . I have a 1980 with a stock motor that has been made into a 383 stroker .

People have been telling me that this gas is better for carbureted engines or should I just stick with the 93 ???

Whats the concensus out there ...

doorgunner

I can only comment on my 2006 Escalade. Ethanol free gasoline increased the mpg from 18 to 21 on the Interstate highways. It costs 25 cents per gallon more, which is a wash on savings, but the performance improvement is obvious.

Douglas Mariani

Stick with the 93

7T1vette

If it's the same C.R. as the original engine, you could use 87 octane with no problems. Ethanol-free fuel might be better due to less risk of some fuel pump and carb parts being damaged by the ethanol.

Mileage will be better with ethanol-free fuel; but cost per mile will be about the same.

All things being equal (cost per mile, fuel availability, etc.), I'd go with the ethanol-free stuff.

cb98coupe

My main concern is keeping the carb and fuel system clean !!!

Whats CR ???

Easy Mike

Truth be told, there is no concensus "out there."

Faster Rat

CR is acronym-ese for compression ratio. The higher the compression, the higher the octane required to prevent detonation.

I never put ethanol in my tank. I add a few gallons of 108 octane C12 race fuel to the Rec 90 because my engine supposedly still has 10.25:1 compression and I like to run 36-38 degrees of timing.

lurch59

Why?

lurch59

I would avoid the ethanol blended fuels. My corvette tank rusted from the inside out and had to be replaced. The Corvette Center who did the work told me they are seeing a lot more of this since blended fuels have been around.

Higher 93 octane fuel is not necessarily better. If you are not experiencing predetonation or spontaneous combustion with 90 octane fuel, there is no reason to increase the octane any further. If I was concerned with needing 93 octane, I'd still stick with the non blended fuel and add octane boost.

The decision to add ethanol is political because it is "renewable" and carbon neutral. As you know, when politics are involved it becomes harder to find the truth....

DABall

I had to replace a 5 year old Holley on my '70 LS5 as the ethanol had melted all the seals and the diaphragm. I have been running ethanol free 91 octane ever since with no problems. It did the same thing to my leaf blower and tractor. Ethanol is a carb killer!

COOLTED

Ethanol sucks. Will never use it if I have a choice... not even in my lawn mower. All of my cars run better with non-ethanol fuels.

REELAV8R

Another vote for non-ethanol fuel. Only run that junk in my modern cars that "require" premium fuel.
I use mid grade as it is much cheaper than premium and my higher altitude allows me to get away with this without detonation. All the mid grade is ethanol blended.

cb98coupe

Just had my carb cleaned out so I am trying to keep it up . I am going to fill up with the Rec 90 and see how it goes .

ddawson

I'm in CA so no other options. The 91 I use that has ethanol has caused no problems in my fuel tank, Q-Jet I just removed or the Quickfuel that was installed.

Iceaxe

When using ethanol fuel my car can become a little hard to start when the engine becomes heat soaked. With ethanol free fuel the car starts super easy every time. I believe the heat soak problem is because ethanol has a lower boiling point than non-ethanol fuel. YMMV

LS4 PILOT

Answer .....

Absolutely



If you could have seen what it did to a mint 45 year old Honda gas tank that never seen rust .....and smell it ......you d never put it in another metal tank anyway.

Vettereturned

I've use both 93 and non-ethanol didn't notice any real performance change with me tired base 350/300. However, it never came to me that the car is a PITA to start after it had heat soaked with 93. I will go back to Non-ethanol to help eliminate this problem - thanks for the post and hopefully solving my annoying start up problem.

68/70Vette

I think you should use ethanol free fuel. I think the ethanol will corrode C3 technology fuel components....particularly the pot metal carbs. Well ...ethanol will not contaminant pot metal carbs, but the water it attracts will. For my 68 which is in sort of a hangar queen status, I buy ethanol free racing gasoline at about $10 a gallon here in Cali. Actually, street gas is about $4 a gallon due to cap and trade C02 regulations, so for what little I drive the car $10 a gallon is not a problem for protecting the car.

cb98coupe

It's a beautiful day here in So, Fla. . I am going out to take a cruise and put some of that Ethanol free 90 in my car .

Like I said before , my main concern in fuel system maintenance , although I am hoping the car runs a little better . The car feels good but it can always be better .

I will post my thoughts after I run it for a bit .

This thread has been very helpful . Thanks !!!...

qwank

if we had the ethanol free choice here I would use it. as long as you engine can run on 90 octane safely I would do it.