boscomantico wrote:
Plenty of them in the German-speaking countries.
I suppose this is guaranteed ethanol-free (or a very low percentage) and made specially for aviation use?
I spoke with one of the very few clubs in Sweden that use MOGAS and they said that the company they bought from could not guarantee that the petrol was ethanol-free so they had to test at every delivery but every time it did turn out ok. They eventually switched back to AVGAS because of the problems with long-term storage. It was a small club in northern Sweden and they didn’t fly enough to use up their storage tank in reasonable time.
Lycoming specifies at most 1% ethanol (including other compounds with oxygen) for MOGAS approval. I don’t know what the airframe MOGAS STCs say.
What is the difference between this German MOGAS and car petrol, in terms of degradation?
Lycoming specifies at most 1% ethanol (including other compounds with oxygen) for MOGAS approval. I don’t know what the airframe MOGAS STCs say.
I never really looked at this but now realize that self-fueling with cans from your local gas station is only an option for Rotax flyers then. These engines and their airframes allow up to 10% of ethanol.
Mogas is not a normed term, even less so a specification. It merely refers to using car gasoline for aircraft.
AA: it totally differs. At some places, the distributor guarantees no ethanol. At Ozzano for example, or at Mühldorf.
In other places, they don‘t, even though they might be reasonably sure that there is no ethanol in there. It‘s about legalities after all.
aart: not necessarily. In many cases, such fuel does not contain any ethanol. So, as long as the pilot checks the fuel for ethanol content (there are couple of ways to do it, it may be ok for Lyco and Conti aircraft. Personally, I would totally avoid ethnaol even if I operated a Rotax.
boscomantico wrote:
Mogas is not a normed term, even less so a specification. It merely refers to using car gasoline for aircraft.
Right. Lycoming refers (for the European market) to EN 228, which is the specification used for “car gasoline”.
We have a large number of MOGAS threads.
I didn’t realise that formally
It merely refers to using car gasoline for aircraft.
But how does this work
At some places, the distributor guarantees no ethanol
I mean, he can take delivery of a load of car petrol, test it, and if it “wrong” he rejects it? It makes no sense. Either there is somebody who actually makes this stuff, or MOGAS is just car petrol and people cross their fingers and hope…
Anyway, ethanol or no ethanol, it sounds like MOGAS is poor for storage – in any tank other than a totally sealed one, and you won’t find a totally sealed tank anywhere – in a bowser, underground, or in an aircraft.
We used car filling station 4* leaded until it was nolonger available. After a few months on Avgas the UK CAA allowed EN228 if alcohol free. We used that, testing each time, until E10 came in.
I’ve never used it in the Bolkow because of the alcohol damaging the tank seam sealant. I’m thinking of buying E10 and testing it. If it contains alcohol it goes in the car
PS I inherited 20L of late 2016 petrol in December 2020. I’ve offered it for cleaning, still some left.
There is a difference between summer mogas and winter mogas. Winter mogas has higher vapor pressure than summer mogas. Storing winter mogas in a sealed container and using it in the summer, you will get vapor lock more easily. For the same reason, using summer mogas in the winter will cause starting problems (which is the reason for the difference in the first place).
It’s said that mogas is like fresh fish, and must be used ASAP. IMO a huge exaggeration. Perhaps the distributer cannot guarantee that every single line in the spec does not change a tad over time when stored in a car’s fuel tank, but it’s not like the fuel is destroyed.
or MOGAS is just car petrol and people cross their fingers and hope
Pretty much but again you are using it for a type of flying that does not rely on power being available all the time and engines are designed to cope with ethanol, also you tend to fly takeoff & landing on Avgas tank while Mogas tank is burned during 3kft-4kft low cruise (avoids vapour lock and rich mixture)
Maoraigh wrote:
I’m thinking of buying E10 and testing it. If it contains alcohol it goes in the car
I would not start with purchasing fuel labelled E10. E10 means that it can contain up to 10% Ethanol, hence the designation. You might get lucky and find a batch without ethanol, but I am sure the forecourt storage tank will be a blend of many fuel deliveries.
If you are regularly looking for ethanol free fuel in the UK, then I gather that ‘super’ (97/99) unleaded petrol is not required to have ethanol, and therefore is most likely to be ethanol free. Specifically in the UK, I gather that Esso Synergy Supreme+ Unleaded 97 and Synergy Supreme+ 99 do not have ethanol. An excerpt from their website is below. However, being in Inverness, it appears that you might be out of luck with Esso, but I would survey the other locally availible brands.
Also, perhaps check where the boat marinas buy their fuel, as often boaters would prefer ethanol free petrol.
I feel your pain; as a floatplane pilot, I spent ages trying to find the ethanol free fuel, sometimes in remote locations 
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