My 1968 skylane has about 280 hours on the engine and it runs great. The book says that it will burn 84 octane fuel but I am hesitant to try anything other than 100. Can anybody tell me what the risks are of running it on automotive fuel?. I understand there is an STC that allows 12volt systems like mine to run on auto gas.What does it entail? I heard that it's only a paperwork shuffle. I was recently in Mexico dodging thunderstorms and found my self arriving at my destination with minimum fuel. I had to drive for 3 hours to the nearest airport that would sell me 200 liters (About 36 gallons)of 100LL. But that's a story for another time... any answer will help thanks
Humberto
My experience is good with the STC auto fuel. (it will cost you $1.00 per Horsepower) I have noticed CHT is about 20f higher and the EGT is about 50f hotter using auto fuel. Other than that the performance is ok. I have noticed that the plane doesn't have quite the power as when 100LL is used. During annual the Mechanic stated that the carbon build up isn't there and the spark plugs are clean with out lead deposits using auto fuel. Not saying I like the performance as during the winter here in Arkansas I use auto fuel but during the summer I use 100LL to keep the performance up. I did have the timing on the mags checked as per STC and I do like the auto fuel alternative. I just don't like to use it 100 percent of the time as our old engines are designed to have lead. Good luck
George
My 1956 172 came with peterson's autofuel STC and I run premium unleaded regularly. I have much less problems with leading if I use it at least half the time. I've been up to 10,500 in the summer on more than one occasion and have never had a problem. I do switch to one tank or the other above 5,000 but Cessna's like mine have placards for that regardless of the fuel used to prevent vapor lock.
I do switch to just avgas if I'm going to let the plane set for any length of time since autufuel isn't nearly as stable and I'm very careful about which stations I buy my autogas from. I also use a strainer when putting in autogas but haven't seen any sediment when I buy from a station that sells a lot of fuel (switches the fuel in their tanks frequently).
I worked in Mexico in the early 80's (long time ago) and the autogas they sold at the time in the area I worked wasn't very good compared to the fuel I bought in America. That may have changed but be careful. Also, I've seen several articles and warnings against puttin any fuel that has alchol added. Its hard to buy non-oxygenated fuel (alcohol added) in some parts of the US but when in doubt, I put in avgas.
I wouldn't hesitate to get the STC and use premium unleaded as long as you follow the requirements in the STC. Just be careful where you buy the fuel from.
I'm now in the way to start to use autofuel in my C150 and C172P following I've purchased some STC's from Petersen Aviation. I have already the choosen autofuel of local product which is close to the specification of fuel which is recommended in STC to start.
Please advise for any other things needed to be verify prior to initial autofuel usage in my aircrafts, such as do I need to start by intermixing the avgas with autofuel ? (in which ratio ?) Do I need to replace all sparkplugs with the new ? etc....
Read the STC, I believe that there are restrictions for the use of auto fuel containing ethanol...
James Pugh Wrote:
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> What is recommendation for use of ethanolized
> autogas in C150G. I have the EAA STC.
The battery voltage on your airplane had nothing to do with the Auto gas STC.
I used to use auto gas in my C150 and had no problems... Since almost all of the auto fuel now contains ethanol it cannot be used in certificated airplanes even if you have the auto gas STC.
Ethanol will absorb moisture, corrode the aluminum fuel tank and fuel lines. Ethanol had about 25% less energy per gallon than does gasoline. This means less power unless you enlarge the main jet and less range. Did I say that the ethanol will soften and damage some O rings and gaskets in the fuel system....
