In the US I don’t think a diesel will end up cheaper. Diesel is always more expensive in the US vs gas. It’s the kind of fuel we pump from the ground. Russian fuel has more diesel in the ground mix. Aviation gas is only more expensive right now because of the legacy lead. Only eight refineries can make aviation gas in the US out of 250. When they get rid of the lead and any local refinery can make airplane gas, it will be at least on par with Jet-A price wise. The general price advantage will go away then. Other parts of the world need diesel. Until the FAA allows retro into old airplanes, there will be no profit in a world of maybe 6000 new engines a year between Continental and Lycoming. They need 50,000 a year to pay for the tooling.