EZFlap wrote:I'm saying that I have it on good authority that you can take the ethanol out of the car gas, which should allow it to meet the car gas STC.

EZFlap wrote:...It might be run as an emergency, or in a 50-50 blend with 100LL, but the "unpredictability" is a big enough risk that I am taking this person's advice against running a majority of car gas.

Accident occurred Monday, September 09, 1985 in ISSAQUAH, WA

EZFlap wrote:
I spoke to my friend who is indeed a research scientist, with a fuels and chemistry background. I told him point blank that I had been involved in a spirited internet forum discussion about taking the ethanol out of car gas for airplane use. So he verified indeed that you can "wash" the ethanol out, and the "phase separation" is part of the process that separates out the ethanol. It would be necessary to cool the fuel after "Washing" to precipitate out any remaining water, which I did not know.

While on the subject, it was explained to me that using car gas in the airplane is just not a good idea, regardless of whether you pull the Ethanol out. The problem is (and this indeed has been mentioned on this forum and others previously by other people) that airplane fuel is a predictable and repeatable guarantee of one level of quality. Car fuel is all over the place in terms of quality, different additives, levels and qualities of distillation. Moreover, car gas degrades and changes over time where airplane gas will not deteriorate.

So the big issue is that car fuel can be OK one time, not OK the other time, have one additive one day and another the next, etc. My friend reminded me that the impurities and added compounds do indeed leave varnishes and residuals that can clog up things, where airplane gas does not.

The bottom line in terms of advice, from a person far more technically qualified than I, is that it is not advisable to start running on auto gas. Blending it with airplane gas to stretch a dollar, within reason) may be fine. If you have no other convenient or available option, it's fine as an emergency measure. But a steady diet of car gas will cause problems.

So you all can make your own minds up, but for the sake of being honest and being a straight shooter I must say here publicly that on the advice of a highly educated person (who is a pilot and multiple aircraft owner) I will not run a steady diet of car gas. It might be run as an emergency, or in a 50-50 blend with 100LL, but the "unpredictability" is a big enough risk that I am taking this person's advice against running a majority of car gas.

While on the subject, it was explained to me that using car gas in the airplane is just not a good idea, regardless of whether you pull the Ethanol out.

My late father was a PhD research chemist for a major petroleum company and he had exactly the opposite view - he thought car gas was entirely suitable for the engines we (including his Tri-Pacer and Champ) operate. He thought that the lead in 100LL was a bigger concern than any posed by auto fuel.

Small Tail Caddy wrote:Shit.....so what's it going to be? Last week it was auto fuel all the way.

180Marty wrote:So there you have it. Two different chemists and two different ideas. I think I'll keep doing what works for me.

EZFlap wrote

While on the subject, it was explained to me that using car gas in the airplane is just not a good idea, regardless of whether you pull the Ethanol out.

Vick wrote

My late father was a PhD research chemist for a major petroleum company and he had exactly the opposite view - he thought car gas was entirely suitable for the engines we (including his Tri-Pacer and Champ) operate. He thought that the lead in 100LL was a bigger concern than any posed by auto fuel.

180Marty wrote:So there you have it. Two different chemists and two different ideas