Hey, my BIL put diesel in his boat before going fishing last week. Believe it or not, with about half gas and half diesel he managed to keep it running with the choke pulled all the way out. Does that count as "both"; gas and diesel?
The torque issue that causes a diesel to compete favorably with a gas engine of equal horse power is that there is more area under the torque curve. This means that the torque of a diesel engine is flatter, maintaining a high level over a broader rpm range. This, in turn, means that the diesel produces more hp than the gasoline engine at all parts of the rpm range except at the rated rpm of each engine. At that point only, does the gasoline engine produce the same HP as the diesel. This is a demonstration of tractability - the diesel HP is easier to use. It absolutely cannot do more than a gasser of same HP if the gas engine can be maintained at an appropriate rpm. This is almost impossible with a gear transmission, but becomes more likely when comparing the use of automatic transmissions on each, and can be identical with both transmitting their identical peak HP thru HSTs where "gearing" can be varied infinitely. A gasoline engine having greater horsepower will always outperform a lesser HP diesel if the transmission/operator combination is sensitive enuf to use the narrower range where the gas engine produces its peak --not very difficult with an HST.
