Forfoxake wrote:So unleaded (or premium) 95 should be OK for a ULS. However some brands of super have the advantage of 0% alcohol whereas 95 has to contain alcohol unless it is from a low volume supplier (this concession is UK only I think.)
I have a niggle and it's based on no more than gut feel, that the length of time super unleaded lies in a tank with less throughput may come close to neutralising the benefits over using fresher regular unleaded. Particularly through covid times. At least in frugal Scotland!
I know there are other ways of checking ethanol, however the easiest is testing with an ethanol soluble dye. We used to have a kit with a purple dye on 'cotton buds'. Would anyone know of a source?
I think I can save you the trouble. In my experience, all unleaded petrol in Scotland contains alcohol-it all comes from Grangemouth I believe.
Fortunately, it all appears to be E5 at the moment. It will be more of a problem if/when it switches to E10 but the test cotton buds will presumably not detect the difference- you will need to use the test tube method for that.
When E5 was introduced in Scotland, some super unleaded (super plus in the Rotax SI) remained alcohol free for a while eg at Esso Stations. Hopefully, this will happen again and we can use 98 RON with only 5% alcohol for a while. Otherwise, it will have to be Avgas until the LAA (if applicable) produces an E10 approval procedure and you carry it out on your aircraft. However, despite the fact that Rotax approve E10 in the 912 series engines, I am a bit reluctant to use it in my airframe so am looking to source a supply of UL91.
PS Glenrothes already have UL91, at a bargain price atm.