I've never seen this test done before. Thanks so much for bringing it to a wider audience - I'm sure it will be useful. All fuel here in the UK has ethanol in it now but we can still buy 5% on the more expensive pumps.
I apologize, I thought this was about cars. However I did learn something important, so now I have to redesign the gas tank on the motorcycle I built from scratch.
We still have ethanol free 91 available in Alberta fortunately. I fly two different machines with fiberglass tanks, and so I have been checking for ethanol since it was legislated many years ago. If/when I can’t get ethanol free fuel anymore, I will be replacing the fuel tanks.
It’s unfortunate that the alcohol content of the fuel is not clearly displayed on the gas pumps - leading many people to be unaware of the recent changes with potentially disastrous consequences such as engine damage/failure.
It would be proper for the gas stations to label the fuel correctly, however it is automobile fuel and not aircraft fuel. Electronic self tuning car engines using plastic fuel tanks are actually not real fussy about what the engine consumes. Our aircraft are definitely fussy about the fuel we burn. As pilots we must be more vigilant than ever before on what goes in our fuel tank. Thank you for your comment.
I believe 91 is specifically a blend of alcohol and gasoline that's only for use in cars specially tuned for 91. I could be wrong, but I don't wanna be.
I believe the two types of ethanol are pretty much the same, one variety has a slightly higher octane rating. We have been traditionally been using 91 octane, no ethanol car gas in our non certified aircraft. I have an antique car with a metal fuel tank, lots of corrosion in its fuel tank coming soon!
All fiberglass fuel tanks need to be replaced and made unserviceable: we had an accident where the fiberglass tank leached resin into the fuel causing an engine stoppage with a subsequent forced off-field landing. Strong words I agree, but I stand by them 100&. The unfortunate pilot DID survive, but has since stopped flying.
In Canada we use the A.K.I (anti knock index) gasoline rating system. I believe Sweden uses the R.O.N. (Research Octane Number) . Our regular grade 87 would be roughly equivalent to your 91-92 grade
Wouldn't running 91 still be a good idea to fight against the loss of octane over time? Though I guess there's no reason to pay more if you know you're going to burn it off ASAP. BTW my local Shell's 91 is still ethanol-free according to my expensive little water bottle.
