Avoiding Pinging with 91 Octane California Gas

[Ron61]

If you want to take the time, they have several videos on You Tube where they tested various fuel additives and show the results. I will stay with the racing gas in my car as I tried a few additives and none of them helped.

Ron

[Bryan Wilson]

In Australia where I am all Mobil stations have 91 and 98. My car runs like a dog on the 91 so I use exclusively the 98 which I can get at any Mobil station.

[olddog]

E-85 is a fairly high octane fuel. Its biggest problem in my area, Ohio, is that it is blended anywhere from 50% gasoline to 15% gasoline. It is my understanding that 15% gasoline (85% ethanol) is difficult to start in cold weather. So from one tank to the next you never know what the blend is.

I have heard of dirt track racers running E-85 with a carb. I have also talked with people who set up 1989-1995 5.0 Mustang to run E-85 with the old EEC4 EFI. The biggest issue is the variability in the mixture, which is why the new flex fuel cars have a sensor that measures the mixture.

That all said, California may have a more stable mixture. So this may be an option, but you will have to check into that. Get the facts first.

Your fuel lines would have to be the correct material. If your running a carb, you may have to get an alcohol rated carb to be able to meter the extra fuel.

Wish I could give more knowledgeable useful information, but I have no hands on experience.

[twobjshelbys]

Originally Posted by olddog

E-85 is a fairly high octane fuel. Its biggest problem in my area, Ohio, is that it is blended anywhere from 50% gasoline to 15% gasoline. It is my understanding that 15% gasoline (85% ethanol) is difficult to start in cold weather. So from one tank to the next you never know what the blend is.

I have heard of dirt track racers running E-85 with a carb. I have also talked with people who set up 1989-1995 5.0 Mustang to run E-85 with the old EEC4 EFI. The biggest issue is the variability in the mixture, which is why the new flex fuel cars have a sensor that measures the mixture.

That all said, California may have a more stable mixture. So this may be an option, but you will have to check into that. Get the facts first.

Your fuel lines would have to be the correct material. If your running a carb, you may have to get an alcohol rated carb to be able to meter the extra fuel.

Wish I could give more knowledgeable useful information, but I have no hands on experience.

It's much more than this. E85 is not a substitute for "octane". You cannot simply take an engine not designed for E85 and run E85. Besides the corrosive component on fuel pump, lines, etc, all of the fuel delivery system will be wrong. Since the energy content (per unit volume) of E85 is much lower you will need at least higher rate of fuel delivery to compensate. (Either a carb or higher flow injectors). If fuel injected you would also need a correct "tune". Flex Fuel (Ford's name for E85 vehicles) detect the use of E85 automatically and make engine adjustments accordingly.

[1985 CCX]

Lucas products makes a bump additive I think? Used to use it, was great.
I am lucky as 93 easy to find on this coast and Cam2 is available at pump 108 octane.

[jhirasak]

Thanks to all of you that have responded to my questions. After reviewing material available on the web, it appears that gas additives that contain MMT provide the best improvement in raising the octane rating of straight 91 octane pump gas. Now comes the problem of separating advertising hype from actual results. However, mixing 100 octane gas with 91 octane normally available in California seems to be the preferred solution to my situation by many on this forum.

Since I would like to keep my existing ignition advance curve for best performance, I think that I will purchase a few gallons of 100 octane gas whenever I happen to be near a source of such gas and keep a can of octane booster with me to add to the tank when I can only obtain 91 octane pump gas. Since I have a MSD Knock Alert detonation sensor installed on my engine, it is easy to to determine if the current tank of gas has a sufficient octane rating.

Cheers,

John