I can run 100LL, mogas, or UL91
You mean you can run
Just trying to avoid any ambiguity here 
Peter, here is a map of airfields in Germany and neighboring countries selling ethanol-free premium unleaded for aviation use:
https://www.daec.de/media/files/2023/Sportarten/Ultraleichtflug/Grafiken/D_mogas_310523.pdf
Just because it doesn‘t exist around you doesn‘t mean it doesn‘t exist at all.
Our Debonair can run this fuel without any limitation on service ceiling etc., and Jan Brill practices this extensively in his Bonanza. You will hardly find a more prolific SEP flyer using the absolute maximum of the performance envelope of his plane.
Peter wrote:
You mean you can run100LL
forecourt car petrol, from any forecourt, anytime of the year, and you have a means of transporting enough to fill your tanks, and you can reach your plane’s operating ceiling, in the summer
UL91
Sure can, why not?
For refilling try searching fuel bags on Alibaba without the 40 thieves… I have 2 of them, 30l each, which I usually carry along on foreign trips. As to the service ceiling, the 21Kft of my steed are seldom of any use, jumping over Mt Blanc at 18K has always worked
Thanks for that map @mri, it now resides in the User Documents in my SkyDemon. I’d wish each country would have such a map.
Peter wrote:
Just trying to avoid any ambiguity here
It’s exactly as @Dan said, but one clarification – I personally have only used mogas from either my local BP station which claims it’s ethanol-free (which I don’t entirely believe) or from “mogas” pumps at airports. IIRC, I’ve bought mogas from airports in ES, DE, CH, FR, IT, and NL. I think Dan’s method of using those rubber bladders is a great idea, but I have not yet gotten around to buying some. I’ve got the good old-fashioned jerry-cans that I leave either in my hangar or the back of my car.
My TB20 takes 86 USG. How do you do that with jerrycans? Even half that is totally impractical.
Peter wrote:
My TB20 takes 86 USG. How do you do that with jerrycans? Even half that is totally impractical.
Well, it depends.
In our gliding club, if only normal flying is predicted, the club manager or somebody crabs 4-6 jerrycans and goes and fills them up.
afterwards its either poured into a large tank with a pump or used 2-3 cans at a time for a towplane. When we have bigger event, we use 200L drums and a trailer. We also have a pump that can be used with 200L drum.
The owner of a RV-10 uses 1000L fuel bowser. I myself use 110L emilcaddy with a pump (plenty for typical rotax-powered 2 seater), also was quite OK for PA28 (ca 4 hours of flying to a typical 45min trip to refill the emilcaddy).
The guys based at EETN use 400L tank on a trailer.
On practicality – in EETU the 100L pump is working only during AD op hours- which is about 6 hours on most days, closed on saturday (but we can fly when the aerodrome is closed). So it makes a good sense to have your own stash at the aerodrome. In EETN the 100LL pump is operated by the same guys who serve CAT planes, often meaning 1-2 (sometimes even 4 hours) wait times to be served. A trip with the 400L tank and trailer takes about 20min ..
Peter wrote:
My TB20 takes 86 USG. How do you do that with jerrycans? Even half that is totally impractical.
I agree, it’s a hassle, which is why we need to push hard for unleaded fuel at the airport. Many Swiss airports have a towable fuel bowser. I’ve also seen these in DE and FR.
Well, my steed only takes 142l total (sans aux tank) and only burns around 21l/h at my settings (I’m in no hurry, hate waste therefore love efficiency, and love the act of flying in itself).
My field has a Mogas pump, and though the gas is more expensive than outside, I use it out of convenience and to support the airfield. Then I usually try to land on UL or small fields where I have a car at disposal, or super handling as on Palma de Mallorca 
Using these kind of fields present many advantages such as reduced or no fees, no handling or slot, and usually very friendly people reselling Cargas, or driving you and some canisters to the nearest station. Yes, it is more work than just pulling the hose from a pump, but saving up to a 1/3 makes the process attractive enough for people on a budget.
Thread drift alert…
There are many different ways of practicing GA. Example: using obsolete fuel guzzlers to play IFR or airliner in VMC (alternatively staying on the ground if serious IMC is present) in and out of airports associated with all the burden and complain about the costs, handling, etc, here on EuroGA. Another GA way is to use what’s remaining in freedom and observe the ground and nature’s features whilst flying below the clouds, and land at smaller fields to enjoy their friendliness, and make a happy report of the experience here, on EuroGA.
The best thing about all of it, is that unless one has to fly say for business obligations, the choice is yours: parade or fun
I agree, it’s a hassle
It’s way more than a hassle. It’s an indication of how far GA has sunk into Stockholm Syndrome (not to mention I am allright Jack.) that anyone thinks that would be even remotely practical.
86 USG is 16 jerrycans, each weighing best part of 20kg.
The point I am trying to make is that if 100LL disappeared, so would large chunks of GA. Forecourt petrol is not suitable for most GA. Too much crap added, no assurance of how much, it can change at any time, it leaves residues, it needs decent stock rotation (avgas keeps for ever in an unvented tank). A proper replacement needs to be found – 100UL thread.
Peter wrote:
My TB20 takes 86 USG. How do you do that with jerrycans? Even half that is totally impractical.
looking with envy at TB20 fuel capacity
Many RV10 s over here are fuelled with jerrycans. It’s only 60 USG of gas. You just get used to it
