Fuel Choices

[BobM]

I have been using premium grade gas from local gas stations for my tow planes (90 % or better octane), mixing in Red Line oil at a 40:1 ratio for my DA engines. The gas has ethanol in it though.

Recently I have been seeing some suggestions of using ethanol free gas. Some people are using aviation fuels, pure gas that is close to 100% octane, sourced from airports or similar I think.

Availability of ethanol free gas depends on location. I know of an ap for cell phones called Pure Gas, which seems to locate ethanol free gas sources pretty well.

I wanted to see what others are using for their fuel.....are you using gas with ethanol or ethanol free ?

[Stew2]

With ethanol, but we run a lot of fuel through the Bidule, so it doesn't sit in there very long.... No problems. 93 Octane, 40:1 redline. With running a ZDZ 180, 93 octane is recommended/required due to high compression.

[Sinkhappens86]

We have a couple gas stations near us that have ethanol free. This is what we try to run in ours.

[BryanB]

If you're lucky enough to have a gas station close by that has ethanol free fuel you're golden.

https://www.pure-gas.org/index.jsp

I live in the major metropolitan area of Houston "Harris Co." so we don't have an ethanol free fuel source for about 100miles. Therefore, I use racing fuel (VP fuels C9) from a local shop.

https://vpracingfuels.com/product/c9/

It's expensive ($10 gal) but I run it in all my small engines both mixed and unmixed, mower, weedeater, chainsaws, generator, etc. and especially in my gasser RC's.The fact that I can let it sit in my carburators for months and they start right up makes it worth the cost. Especially in my generators and model airplanes.

BB

[jfrickie]

3W-170.....ethanol free premium or ethanol free regular.....50:1 Sthil HP Ultra. Both grade are in abundance where I live.

[Swiss1]

For what it's worth, I've always been told that small engines do not gain any performance advantage from higher octane fuels!
However running ethanol free fuel will stop premature hardening and breakdown of fuel lines o'rings etc. this is what I use on my DA's, as is readily available in our area!
Just my 2 cents worth.

Jeremy and Ben
SCCAAA TT TN

[Stew2]

The higher octane isn't for performance, it is to prevent detonation or pinging due to the high compression. It will maximize the life of the piston.

[Swiss1]

Got it, never seen the specs for ZDZ!

[AGriffith]

We dont run high enough compression to worry about running super.

[Steve P]

The comments were specific to the ZDZ-180 where premium is the manufacturer spec

[Stew2]

The ZDZ instructions specify 93+ octane.

[BobM]

Many thanks for all the input from everyone, very helpful. Sounds like going with ethanol free gas is the way to go if possible.

[Rich Kardian]

100 oct Aviation fuel is what we run. Most any airport FBO will let you buy it. The high octane number is to control detination in "Large Bore Engines" and compression ratio has almost nothing to do with it. The main reason to use avgas is no ethanol and NO SMELL OF GAS in the car. Price is about $ 6.00 a gallon. Note that you do need a large inlet on the fuel container to be able to fill at the airport as the standard little ones won't work. 40:1 Redline per DA's instructions. We also have ethanol free available at $ 4.00 a gallon but again WITH gas smell.

[kd4jaz]

100 LL aviation fuel has 2mg of tetraethyl lead per gallon. This will lead up an engine pretty quick. Also, 100LL is was designed for lower revving aircraft engines. DA specifically says NOT to run aviation fuel. As Stew2 says, if you are moving E10 through the engine without long times of sitting in the hangar you wont have any issues. The older lower compression 80 octane aircraft engines had a rough time running 100LL, I had an 80 octane engine and know about it first hand. You could run 80 octane avgas in a car and it wouldn't ping, avgas and mogas octanes are calculated differently. Also 100LL avgas main ingredient is an alkylate which doesn't always play well with Walbro rubber parts. I've experimented with all kinds of gas mixes and believe it or not, regular pump gas works just fine. I will agree that avgas doesn't smell near as bad. Just curious, what part of the country are you in that Avgas is $6/gal and Non-Ethanol gas is $4/gal. That seems very expensive. Here in Fl Avgas runs about $4.00 and Non-Ethanol about $2.85