Fuel systems and auto parts
 

I will use auto fuel. I thought this was straight forward, but I have found out by now (thanks in large part to this board :) ) that this is not as straight forward as I thought. For instance, Ellison TBI cannot be used due to chemical incompatibility between auto fuel and materials used in the TBI.

More in general terms I also got the understanding that AN fittings not neccesarily are compatible with autofuel. I have no idea if this is "just the specs", ie they are only spec'ed for AVGAS but there are no physical or chemical incompatibilities with auto fuel, or they are only spec'ed for AVGAS because there really are chemical incompatibilities, like the Ellison. I also wonder if there are any difference bewteen fittings vs AVGAS and Jet fuel.

Maybe it is better to use automitive fittings?

Auto fuel
 

AN fittings work fine with auto fuel.

That's a shame that the Ellison TBI does not work with auto fuel. I read that on their website, but they don't say which components will have trouble.

Auto fuel?
 

This is a first! At least here and right now, there is no reason to use auto fuel! I am filling up my airplane with 100LL for less per gallon than my wife's car which takes premium. ($3.69 vs 3.79.) Since the few airports around that sell auto gas charge more than the local service stations, 100LL is a bargain. I never thought I'd say that.

Bob Kelly

Won't last long that way either, enjoy it for now!!

That's a distinct possibility - but I too would rather have the option. I'll be running FI and build my tanks with a return line (capped until needed), to be able to take advantage of whatever changes in the market should transpire. You can always run on higher octane and just use a lead scavenger - but if you're set up with 9.2:1 or the Ellison TBI, you're SOL and stuck with 100LL.

Fuel at my home base is always at least a dollar a gallon higher than auto fuel.

I wish. Here in Norway AVGAS is 6.6 US$ per gallon. Auto fuel is about 4.7 US$ per gallon on aircrafts. Jet A1 is about 4.4 US$ per gallon (for private use). This may change, but most probably for the worse than for the better regarding AVGAS. Not planning for auto fuel when I have the possibility is not a vise thing to do. In fact, not planning for the possibility of using Jet A1 sometime in the future (or even right now) is almost to the point of being an unvise thing to do.

I emailed Ellison FLuid Systems. They said it was rubber gaskets and things that would have it. They also said they had no plans now or in the future to change the materials affected.

Good to hear that AN fittings work :)

Since you are in Europe and not in the US were there are so many misguided attempts to make an eco-friendly gasoline (which all fail totally) you may be able to run local auto fuels. The thing that Ellison is worried about is ethanol. Ethanol attacks many gasket materials and some kinds of rubber. Otherwise check to see if your local gasoline contains oxygenates. (oxygen bearing additives) if your goverment is eco-sane than you can probably run auto fuel just fine. The base stocks are the same. There is nothing magical about 100LL! In the US we find that several areas have widely varying formulas. Lycon a top local engine builder doing both stock and modified Lycomings say that after testing 100LL throughout California the formulas have been "fooled with". They don't trust the stock of 100LL now. They will void your warranty if you run L-O-P since the fuel stocks are suspect. This is not a big supprise since avgas is such a tiny percentage of their total flowage. One of the majors (fuel suppliers) told Lycon the total sales of avgas for the YEAR is about the same as the auto fuel they sell in one DAY! This dosen't mean that your dealer is trying to sell sub-standard fuels, just that the TEL (lead) and other components that they use to make up 100LL can vary considerably. These guys build engines for Sean Tucker one of the best acrobatic airshow pilots around, and have a great rep for knowing their stuff. From what they were telling my EAA chapter auto gas may be MORE consistant than avgas. Find out what is in your local blends you may be able to use it.

Bill Jepson

PS. and YES AN fittings work FINE! I wonder where these rumors get started!

That's what I thought as well, but now I am going for FI. Alcohol in the fuel is not very common in Norway, but in the EU countries there is a lot of it. There is also this new fuel coming, E85 which consist of 85% ethanol and 15% gasoline. But the amount of diesel cars has exploded in the last 5-10 years, and it looks like diesel will take over completely rendering ethanol irrelevant in any case (not that it ever has been relevant :) ).