Question about gas

[ibgarrett]

Yup - I think the EPA is circling the wagons to take this one on... The part that is going to be somewhat entertaining is that if it comes down to the EPA or TEL disappearing the price is surly going to spike and spike hard. All of us will just smile and use the alternative fuels...

[PilotMelch]

Dang, there are SOOO many more downsides to ethanol than these, and they are bigger.

I'll add that with Ethanol you may not know what your octane rating is. Ethanol, like all alcohols, absorbs water. When it does, it affects the octane level, and not in a good way.

Then there is the fact that Ethanol doesn't have the same energy density as raw gasoline. This means you will have slightly less performance and range than with gasoline without Ethanol.

Some pilots also have fiberglass fuel tanks (not the slight of course). The Ethanol does, over time, eat epoxy. Coated tanks aren't immune, but a good coat of Jeffco Sealant does mitigate this to a large degree. Epoxy structural adhesives aren't immune, though. Did I say "structural"??!!

The problems most commonly referred to are the problems with rubber and shelf-life. Some pilots "get away" with using Ethanol because they fly often, which changes up the fuel often, and don't have a lot of rubber or other susceptible materials (fuel lines, gaskets, o-rings, etc.) -or- there's a looming problem that aren't "yet" aware of. We get lulled into thinking it's OK when there isn't an immediate correlation. The effects of Ethanol on a plane can come "later".

But this ignores the other, bigger issues I mentioned at the top.

Just say NO to Ethanol and your plane and engine will run better and last longer!! It's not worth the slight savings.

Find airports that sell unleaded fuel (MOGAS, UL94, and soon G100UL) at flyunleaded.com

[Joe Azzarelli]

I don't believe this point was brought up in this discussion. But since I just skimmed the responses I might be wrong...

One of the shelf-life issues for unleaded mogas is the chemicals used to take the place of lead to prevent knocking tend to evaporate faster than the fuel. The quality of the seal of the tanks can affect how fast this happens.

If you keep your plane on the ramp keeping your tanks full will help.

[ToddJohnson]

I flew a Europa XS with a Rotax 912 for 7 years. I flew over 500 hrs and I think I used 100LL in it less than 10 times. All other flights were done with premium auto fuel, more often than not with 10% ethanol….because that was what was available. I flew in temps from 10-115 degrees and never had an issue with engine/fuel. I’m building a TSi and plan on using pro seal on the fuel tanks and using auto fuel.

[Skepilot]

I flew a Europa XS with a Rotax 912 for 7 years. I flew over 500 hrs and I think I used 100LL in it less than 10 times. All other flights were done with premium auto fuel, more often than not with 10% ethanol….because that was what was available. I flew in temps from 10-115 degrees and never had an issue with engine/fuel. I’m building a TSi and plan on using pro seal on the fuel tanks and using auto fuel.

The 915 turbo demands more fuel flow than the 912. As such, suction is increased in the fuel lines, lowering the pressure, making vapor issues with mogas more likely.