Autogas in the future.
30 yrs ago in Italy bought 1967MBZ SL which was converted to AutoGas. Still had regular gas tank. Great flexibility. With both tanks, I could go anywhere in any country. In all of Italy I could fill up with AutoGas but in Greece and Turkey, only gasoline was available. Car ran really, really clean and all sorts of combustion residue in engine was cleaned away by the AutoGas use.
Chuck