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Will the go-devil run on 100 octane gas? I found most of my M38 fuel issues boiled down to 3 years of ethanol sludge in the what had been a new tank (pickup was clogged, made the carb appear to need rebuild, caused to mechanical fuel pump to fail). One new Solex carb and a new electric fuel pump later I went back to the problem – the tank. I don’t want to do this again, a baffled tank with no bottom access isn’t fun to clean out. I have 100 octane gas, low leaded with NO ethanol – they call it blue gas available 2 miles down the road. It is very costly $5.70/gal but since this “parade jeep” sits more then it runs I thought it might be the way to go. Or, at a least mix, maybe 50/50, along with treatment. I didn’t find any mention of required gas in the TM9-8012

There wasn't a required gas listed. Just the minimum octane rating of fuels that was allowed.

100LL avgas works fine when mixed about half and half with auto gas. The goal is no ethanol period but for those without access to non-ethanol aut gas you will be stuck with a wee bit of ethanol.

The 100LL Avgas stores very well compared to any of the auto gases. I am an aircraft mechanic by trade and I have rescued aircraft in storage over 15 years with no degradation of the 100LL at all. Aircraft owners prefer to not use any gas more than 2 years old but that is good for me since I buy it at half the going price and use it in all my garden and farm vehicles and my M38 and M37 mixing half and half with auto gas.

The 100LL can run very hot and cook exhaust valves if used for a lot of high rpm highway driving if you don't water it down with auto gas.

Most states do not road tax aviation fuels but they also have laws against dispersing it or using it for on road use.

If you do run 100LL be sure to advance your ignition timing another 5 degrees.

I did find a post you had in 2012 - basically said the same. @$5.70/gal I won't be using it straight - @50/50 it drops the ethanol to about 5% and octane to 93-94. I heard the airfield might carry 93 octane - if so I could run maybe 75/25. I work on farm equipment and some lawn stuff and every spring I wish I could count the fouled fuel systems I have to get running. There is still a pile of weed eaters out there that I have to work on or junk if the cost in time is too high to clear the sludge clogs.

I remember when we stored auto gas for years and it still ran. Also mileage loss is directly proportional to the percentage of ethanol - I've had Ford Rangers for years - the engines are much the same year to year as is the truck itself, you can watch the MPG loss as ethanol was added - used to get 29-31 MPG now it is 24-26 MPG.