It is widely attested* that the Su-25 Frogfoot's engines (the Turmansky R-95Sh and later the R-195) were designed to function using a wide variety of fuels, including diesel, gasoline, petrol, kerosene and avgas.
For a rough-field front-line attack aircraft, the ability to load it with whatever was at hand, even tank fuel, would be very useful.
It's not a feature I've read about anywhere else. The question is, what specific engine modifications allow this level of fuel-tolerance in comparison with, for example, the T-34 which powers the A-10, an aircraft designed for a similar role.
Su-25 Grach (NATO reporting name: Frogfoot)