TheSamba.com :: View topic - What's more important

Sun Aug 18, 2019 11:52 am

Not pick at a sore, but in my area most gas contains ethanol. I buy 91 octane, but it still contains ethanol.
Good old Casey's sells ethanol free gas but its octane level is 87.
So which is better for these 50 year old engines?

Sun Aug 18, 2019 1:47 pm

I don’t know about ethanol or not. I use 91 octane. But when I fill up at my Caseys I use the non ethanol. They both seem about the same to me. Which one is better for the engine? No idea.

What are you located that you have a Caseys? The midwest? I’m in IL

Sun Aug 18, 2019 2:12 pm

Just south of Kansas City

Sun Aug 18, 2019 6:04 pm

Unless you have the compression to warrent the use of higher octane fuel, I wouldn't run it if it had ethanol. If I could choose regular grade gas that had no ethanol I would.

brad

Sun Aug 18, 2019 6:56 pm

I don't waste my money on either. :wink:

Tue Aug 20, 2019 4:30 pm

Every gas pump in our area says "May contain up to 10% ethanol." I just pump it in and drive, no issues at all with any of our cars.

My air cooled engine only has a 8.4/1 CR so 87 octane is all it needs.

Fri Aug 23, 2019 12:17 pm

Not enough Ethanol in the gas to hurt anything if you burn all of it in the tank and don't leave car sitting for extended periods.

Bryan

Fri Aug 23, 2019 2:09 pm

All gas line nipples in use on my buggy are copper now, after seeing what early ethanol-containing gasoline did to the puter nipple on my lawn mower's Briggs & Stratton carburetor, which sat un-used for less than 2 months:

Oh, and going into that carb was a rubber hose which had turn'd into something like nutty puddy. Bottom line, I use ethanol free gas for lawn equipment, regular regular for my buggy.

Thu Sep 05, 2019 2:38 pm

I recently did a little experiment: Both my Mercedes and Smart require premium fuel (91oct here in Utah). "Clear" (ethanol free 88 oct) is the same price as premium. I ran 2-3 tanks in each and found I get 2-3mpg better in both with the Clear.

I run it in both my Beck (CB Performance 2.0L) and my Ducati as well. Both "hibernate" in the winter. 3 years in a row, my Ducati starts right up on the first warm day of spring, as opposed to taking an afternoon to get it started back when I used regular gas.

Thu Sep 05, 2019 4:31 pm

Those are both European cars so my guess is they require 91 RON gas which is the same as 87 octane here in North America.

The mileage difference is does not surprise me. Premium is a slower burning fuel and if your engine does not require it then there will be no benefit and probably a loss.

Fri Sep 06, 2019 12:40 pm

oprn wrote: Those are both European cars so my guess is they require 91 RON gas which is the same as 87 octane here in North America.

The mileage difference is does not surprise me. Premium is a slower burning fuel and if your engine does not require it then there will be no benefit and probably a loss.

93

94 for my Porsche

Sat Sep 07, 2019 1:44 pm

Note that ethanol is only about 1/2 as energy output efficient as the same volume of gasoline. My son thought that since his Ford Ranger is "Flex Fuel" and thus able to run on either commonly available 10% ethanol gasoline or on E-85 and a local to his work dealer sells E-85, at a cheaper price per gallon than for 87 regular, that he would put in the E-85 and save money while getting a supposedly "better" fuel. He quickly learned that I was actually right that his fuel economy would go down dramatically. He was using so much more fuel that he was spending a lot more money on the E-85.

Maybe Dad really DOES know something? 8)

BTW... regarding octane ratings:
In the US, Canada and some other countries, gasoline (or more correctly stated: "automotive fuel"), octane ratings are calculated as MON X RON / 2. Motor octane times Research octane divided by 2 which is the average of the 2 methods. This is also known as "AKI". Most of the rest of the world uses RON. So for a European car, a stated octane requirement may be a RON octane, which may confuse folks in AKI countries.

A related note, while in Utah on a rececnt vacation, I noted that most gas stations had "regular gas of 85 octane, and mid-grade as 87 and Premium as 91. While in California where I live, Nevada and Arizona, I find Regular as 87, mid-grade as 89 and Premium as 91. All of the above as 10% ethanol. Non-ethanol is not generally available at public pumps and E-85 is rare in SoCal where I live. Only 1 E-85 dealer in this High Desert area of nearly 1/2 million residents.

Sun Sep 08, 2019 9:45 am

dustymojave wrote:
A related note, while in Utah on a rececnt vacation, I noted that most gas stations had "regular gas of 85 octane, and mid-grade as 87 and Premium as 91. While in California where I live, Nevada and Arizona, I find Regular as 87, mid-grade as 89 and Premium as 91. All of the above as 10% ethanol. Non-ethanol is not generally available at public pumps and E-85 is rare in SoCal where I live. Only 1 E-85 dealer in this High Desert area of nearly 1/2 million residents.

When I lived in NY, they likewise had 87,89,91, with the added bonus that most Sunoco stations had 94. My 968 loved it.

FWIW, other than noting mpg over the long term, I've never been able to tell much difference in octane in my vehicles. The exception is my 968 which has knock sensors. When I lived in Las Vegas, a few Rebel gas stations had 100 octane racing gas in their pumps. Mixing it 50/50 with 91 octane (because it was friggin $8/gal) I could feel a noticeable increase in performance. I wish someone up here sold it (the only 100 octane you can get is 100LL at the airport. No good for cats) As little as I drive the 968, it would be worth it.

Sun Sep 08, 2019 9:55 am

MrGoodtunes wrote: Bottom line, I use ethanol free gas for lawn equipment, regular regular for my buggy.

Pull the gas line off your carb and run a Q-Tip down it. After someone on a boat forum I read posted the picture of "pepper" in his fuel filter, and his dissected priming bulb that was disintegrating into black powder, I checked mine and it was likewise disentegrating into the gas. Had to replace all the rubber lines in the motor and the disintegrating fuel pump diaphragm.

I replaced the leaking float bowl O-Rings in my Ducati carbs two years running back when I used E10. Two years running they've been leak free running E0. And it starts right up in the spring, rather than if being an all-day affair to start it up like it used to be.

I run ethanol-free in all my vehicles now.

Sun Sep 08, 2019 2:55 pm

dlearl476 wrote: When I lived in NY, they likewise had 87,89,91, with the added bonus that most Sunoco stations had 94. My 968 loved it.

FWIW, other than noting mpg over the long term, I've never been able to tell much difference in octane in my vehicles. The exception is my 968 which has knock sensors.
Yes your 968 has a high compression ratio engine and is set up for premium fuel. All three 944s in our yard have this sticker.

Tue Sep 17, 2019 12:55 pm

I make sure before mine is stored for the winter to run the pump gas out as much as I can and refill with eth-free. That however is only because in my experience, "real" fuel stores better and is easier on fuel lines and gaskets.

Tue Sep 17, 2019 4:18 pm

91 RON is equivalent to 87 AKI (US and Canada fuel rating). :wink:

Tue Sep 17, 2019 5:19 pm

wythac wrote: I make sure before mine is stored for the winter to run the pump gas out as much as I can and refill with eth-free. That however is only because in my experience, "real" fuel stores better and is easier on fuel lines and gaskets.
That is my routine for the '57 Bug and will be for the buggy when it's gasification is complete. The last 2 tanks before winter storage are ethanol free and the last tank is spiked with Sta-Bil. During the year I run E10 and haven't had a problem.

To the original question, with a stock engine I prefer 87 octane. Having an appropriate octane level is more important than avoiding ethanol. The Bug engine doesn't tolerate pinging well. Obviously a lot of Bugs have been handling E10.

Sun Oct 06, 2019 8:29 am

If you are using stock carb jets.. Ethanol free fuel is the better healthier option for your older gasoline engines. Leaner running engines in general.. give more power.. but has a by product of heat.. which our air cooled engines .. dont like..

A few years ago when I put my Corvair'd Volksrod on the road, I found it ran the strongest on 93 with 10% Eth...and pretty good. . but had an annoying lean surge and tip in hesitation... Marvel Mystery or ATF in the tank helped it some so figured it was due to the dry Ethanol content. When I finally got around and decided to re jet it with larger main jets (390 Holley) .. they cured the issue ... However...when No Eth gas started to make its easily available return to our area .. and I dropped in a nice tank full of 89 Pure Gas.. .. it ran like shit.. Overly rich.. couldn't tune it out.. and it had that old car exhaust smell .. I drained and used it in the lawnmower and motorcycles.. Dropped 93/10 back in.. and it was back to normal... I stick to MM in the tank in it now ..:lol:

Stabil products work well. Ive used them all.

Marvel Mystery in the tank... works well to keep the fuel system lubed up... It cured a carb slide valve sticking problem I had on a CB750 Four.. on the fist tank treated ride.. .

To advise on the question.. octane or ethanol free.... use what runs the best for your engine application.
Depending what you use it in... IMO both are important..

.

Wed Oct 30, 2019 9:03 am

Ive never had a problem with 93 premeum with ethanol.although I did plumb the car with good marine fuel hoses where ever rubber was needed.