Are there any issues with running airplane gas in cars? There is a small airport by me that sells 100 octane airplane fuel that is ethanol free. This is the only ethanol free gas that I can find locally . Would this cause any issues with the motor, carburetors or fuel pump?

hi
oce you try it you will never go back !

all i have used for last 4 years , no methonal to ruin your gaskets / seals .


you can advance your timing app 4 deg for better performance .

no down side !

Same here,101 low lead,9 mi away and last Saturday,$4.35 gal. Been running it exclusively for the last 15 yrs,no dirty tailpipe either !

Uhh, if an engine makes peak performance with 91 octane and 35 degrees of ignition timing, running higher octane and more spark timing will not improve anything.
People have the false impression that higher octane will automatically make your car faster. That is only true if the engine is modified with higher compression and if the gas they buy at the gas station does not have enough octane to allow a decent timing curve.
People with a 10 to 1 engine are not likely to gain anything running 100 octane fuel.

100 LL is designed to be ran at different altitude in the lean condition at low RPMs(below 3000 RPM), it does have a shelf life of 18 months which is good
I use to buy and race on the aviation fuel back when you could still buy 100/115, 115/135 and 135/145 octane
I quit using it when it became a federal offence to use it on any public highway If your caught and convicted it can be a $10,000.00 fine
Are you feeling lucky
Back before it became illegal to run it on the roads I was ask by a San Bernardino County(in CA) sheriff what fuel I ran in my old 1963 415 HP Max Wedge street car, I told him it was Klotz brand race gas He said that he had never heard of that brand but he owned a small airplane and said it smelled just like the aviation fuel he ran in his airplane

That's all I ran in the 1980's. It's cheaper because it has no highway tax added on to it. That's the main reason they don't want you to run it on the road. The local airport workers knew me well back then. Fill up 2 or 3 five gallon cans and off I'd go.

Exactly this. Additionally, its has different density. Meaning, even if you DID need higher octane to avoid detonation, you would like have to re-jet for optimum AF ratio.

Ran it in the late 70's for my 12-1 engine. Ran out of gas one night and put Sunoco 260 in, one mile later the engine quit with a huge amount of white smoke. Took a head off and 3 of the 4 pistons on that side had holes in them...

I will put it in even the lawn mower in the winter so things don't stop up. It has lots of lead which is bad for valve guides. If you drive a lot it can cause valves to stick and will foul plugs, airplanes have a mixture control so that the engine can be leaned out at idle and altitude. On the plus side it doesn't stink and evaporates very quickly and doesn't leave anything behind. I use it to wash parts and hose down my engine when it gets dirty.

Because its made for use at high altitudes, it has a different specific gravity. If you run this fuel you will need to adjust your float levels. This is fine if you run it continuously BUT if you put a tank full in your car, drive far enough to use all or most and then fill up with pump gas, the car will run like crap until you readjust the float levels. Been there, done that. It wasn't worth the hassle. You can run Shell high test - apparently its the only fuel on the market that does not (yet) have ethanol in it.

When I was a practicing A&P in the late 80's/early 90's I was running a 10.0:1 (via milled 302 heads) 318 with headers, AFB, dual plane Wieand, 284/.484 purpleshaft. I'd run 25% 100LL with 85 unleaded (4 gallons of 100LL in a 16 gal tank). Engine really liked that with 37* (6kft) and I could bring it all in by 2500 without problems. I'd have to back off to 34 for 91 unleaded, and couldn't stand on it off the line to avoid detonation. Sure smelled good. I could fill it up with that combination for $15.

I have no performance metrics to share.

So, when I was working in a repair station on Continental and Lycoming airplane engines that ran 10LL exclusively, at 2500hr overhaul we'd knock the plug out of the crank snout and from behind the plug back to where the cranks got solid right before No.1 brg, would be packed with lead. Leather aprons, rubber gloves up to our elbows and face shields were worn while we used aluminum scrapers to literally get the lead out and it all had to go into a hazmat bin.

Lead in the blow-by mixes with the oil and through some act of physics and engineering would accumulate in that part of the crank. I was always told that there is too much lead in 100LL to run it uncut in an automotive application, and that its exclusive use (uncut) on the street would cause long term durability problems due to oil formulations and no place for the stray lead to collect, which would cause it to pack piston ring grooves as well as mucking up the PCV system.

See Frankenduster's post.....he's right.

Maybe in Canada, but all the Shell premium here has around 10% ethanol in it.

Avgas runs okay in a lot of high performance engines but it is illegal to use on the street. So depending on who is paying attention it might not matter or you might get crossed up with someone.

I am more surprised that FBO s or Airports sell it to the general public off the street

We stopped doing that about 15 years ago ?

I have been pumping 100ll into aircraft for 32 years in GRB

Outside of the SE corner, its generally not too hard to find some eth-free pump fuel.
https://www.pure-gas.org/extensions/map.jsp?statecode=PA

https://www.pure-gas.org/index.jsp?stateprov=PA

Don't kid yourself, its still not pre-reformulated gasoline, but it is eth free.
100LL can not be pumped into your car. Nor can most race fuels. They will fill a fuel container.
Most race fuels and Av-gas will store longer than pump fuels. You can use it for off road, (racing) storage or even in your small engines before putting them away.
The downside of 100LL is there is no reason to use it if the engine doesn't need the octane or the lead. Just a waste, and the lead will eventually foul any O2 sensor, etc.

We have a small local airport that has a 24 hour self serv pump. Swip a credit card and fill up!

prob should delete that post.
don't blow it for everyone and the owner

Little known fact here in Canada, Feds a few years back passed in a Omni-Bill a clause that allowed gas companys to say no Ethanol till it reached 4 %, meaning they can legally say No Ethanol in fuel even though it may have up to 3.9 %. Here in Ontario last I checked Ultramar high test was the lowest at 1.5 %. Shell had 2 %. I run Star tron in all my carburetor engines for this reason, better safe then sorry !

The only reason I was looking at running this was because it is ethanol free. I know I won't gain any power from it. I'm just sick of the problems with the ethanol and the carburetors. This station is only about five minutes from my house versus an hour or more for all of the listed stations online with ethanol free gas available.