Diesel
Rob the fuel consumption of a model Diesel is considerably better than a glow engine, I've seen claims here of 20 minutes from an 8 oz. tank. You prop them down to the 8,000 to 8,500 rpm range with the throttle about 80% open. I use a 16 oz. tank to run Diesels in a test stand and rarely fill it above 2/3 and can run most engines over 40 minutes. The compression adjustment is used to adjust the compression for starting a cold engine, lowering it to start a hot engine, different prop loads, large props less compression and small props higher compression, and to a small degree adjust the European style Diesel for ambient temperature changes. The Davis conversions rarely need adjustment after the initial setup unless you change props or there is a dramatic change in the ambient temperature. They run on a mixture of kerosene, ether, and ignition enhancer, and lube, castor mostly. As for longevity, I can only say that my most run Diesel, a SuperTigre .51 conversion is still going strong after being a US Aircore Knight Hawk and Colt 40 my second and third trainers and a Kombat Kopter. It still turns a 12x6 three blade in the 8,800 rpm range.