100 octane av gas

[rpatton3]

My Backdraft has about 1/2 87 octane ethanol free and 1/2 93 octane fuel and a bottle of 107 octane booster. Can we run this concoction safely through my car if we take it easy?

Should I just run this crap through my E-150 and lawnmower?

Is 100 octane low lead av gas safe to use and or mix with auto fuel in my Roush 427 Windsor 515 HP engine. 780 carb, no EFI, no cats so nothing the lead is going mess up. Getting the fuel is no problem and I can ethanol free 93 octane just down the road at a MAPCO Gas Station.

My car has 700 miles since new in 2.5 years; I have been sick and hospitalized four times in 12 months.

I think I asked this before, but no luck finding it on my phone.

Thanks,

Russell

[DAVID GAGNARD]

If your engine has a compression ratio of about 10.5 to 1 or less,straight 93 octane pump gas is all you need...(my street car engine is 10.5 to 1 compression with iron heads and all I've run in it is 93 octane pump gas with no problems in 35,000 miles)....I'm guessing that is about what compression ratio the Roush engines come with........

With that said, yes you can mix 100 octane low lead AV gas with any unleaded gas without any problems, I do it all the time......
I run a 50/50 mixture of 93 pump gas and 100 octane AV gas in my race car, have been doing this for 7 years.....of course no emissions/cats and a carbed engine........

David

[Tom Kirkham]

Not good for the O2 sensor in the E-150.

[Danr55]

Make sure you have ss valve seats!

[rpatton3]

Originally Posted by Tom Kirkham

Not good for the O2 sensor in the E-150.

Thanks for information. The 93 octane and 87 octane are both auto fuel but the octane booster had disclaimers all over bottle.

The Backdraft got filled up by a great neighbor's son who is a pretty good friend. He meant well because he operates lots of small engine equipment. He hates ethanol fuel because of long term storage. He buys ethanol free fuel for his big motorcycle at a marina.

Thanks, Russell

[Roush #1]

I have used 93 octane - mostly ethanol free for 30,000 miles on my Roush 427 SR engine. It has had a tank or two of 91 octane and I am sure some of the time some ethanol (10%) has been added in, but when I check it, it has always been alcohol free.

If you are close to sea level and even up to 1500 feet or so elevation and the temperatures are cool - below 90, good 91 octane will run ok in the 10.5 : 1 compression ratio SR engine with the aluminum AFR heads if the timing is set at the recommended 31 to 34 degree total.

Bunch of ifs there so if you can run the 93 and don't worry.

BTW....if it were mine, I would drain out what you have in the tank and refill.

[Karl Bebout]

I've run the 105 leaded AV gas sold at the local small airport. I add one ounce or Marvel Mystery Oil per gallon of gas for a little lubrication. Never had any problems, exhaust smelled good, and younger people who had never run leaded gas, comment that I must be running very lean since the insides of my exhaust pipes are very light gray.