A C180 with PPONK, mogas, glass, autopilot, leather interior, amsafe airbags, and a fresh retro-style paint job is my dream plane.
…a 170A would be mine…even the 0-300 engine…no need for glass or a/p
If we shall dream 
But when you say Mogas, do you mean car gas without ethanol? Because that’s even harder to find than Avgas!
The future is turbine and electric hybrids. We have to just forget the piston diesel.
I believe ethanol is alcohol and the commonly used fuel tank sealant, PR1422, is limited on the max % of alcohol. Also alcohol attacks fuel system components e.g. o-rings, and plastics in parts like fuel filters.
A Mogas STC doesn’t likely help here because AFAIK it was originally related to the engine alone. An O540 can officially run on Mogas, an IO540 officially can’t (but can run on 91UL).
Yes, but all retrofit Mogas STC’s for Lyco’s or Conti’s are for fuel without ethanol. Petersen doesn’t approve more than 1% of it for their STC. As fars as I know, only Rotax engines can actually use car gas with 10% ethanol (E10). It is virtually impossible to find ethanol free car gas here in the US, where there is less restrictions. It must be downright impossible to do in Europe. Much easier to find Avgas.
VW aircraft can use 5% ethanol. I certainly see the microlight guys with Rotaxen using petrol from the local garage.
AdamFrisch wrote:
It must be downright impossible to do in Europe
Not quite. Especcially in Germany, Austria and Switzerland every small airfield has MOGAS, which complies to this. The Pedersen STC is extremely popular. This was the reason why Pipistrel insists on having a mogas capable engine on their Panthera (all their others are Mogas capable anyhow) and have actually dumped the original IO390 for the IO540 now. MOGAS capability is a huge selling point in Europe, particularly in the aforementioned countries. From what I remember, also in Italy on the various unlicensed airfields there, a lot of this fuel is used.
There you go, learn something everyday! Here in the US, it’s almost impossible to get the stuff. Some guys have their own tanker systems and buys it from refineries direct, but other than that, really spotty. Ethanol is the devil’s work. Should never have been allowed.
There are no technical issues that stops Lycomings from using even 100% ethanol. All complications here are entirely “self made” due to certification. Ethanol safe gaskets, rubber, plastic etc have been “invented” centuries ago.
Ethanol free mogas used to be available everywhere. But since Circle K took over from Statoil, the “98 octane” that was guarantied ethanol free seems to be gone, and all their fuels have 0-5% ethanol (could be 0%, but could also be up to 5%, who knows?). Shell still have ethanol free mogas though, and also Exxon. It’s no problem getting it, but if the local gas station have it, is another question.
According to vintage car owners, the biggest (only?) problem with ethanol (5%) is storage. If must not be stored in the tank of the vehicle during long periods, for instance during the winter. Ethanol will absorb water and it will decompose into acetic acid when also oxygen is available. They recommend filling the tanks fully up with 98 octane for longer periods of storage. I guess the same would be valid for aircraft, only using avgas instead of 98 octane mogas. There are also some special additives, bought at car retail stores, that will prevent this decomposition, but I don’t know any specific products.
