I see a place for both. Without question, the diesel is more efficient for most tasks. I still like gas for some jobs however, and it powers (5) of my (6) tractors. Usually it is a matter of convenience but it also makes for better extreme cold weather starting. My (2) 12 hp lawn tractors are both gas, and there just aint much available in diesels in that size range. I mow less than an acre and can knock it out in under an hour with either one of those tractors (one gear, one hydro), so any more hp would be overkill. My cultivator tractor (Farmall Cub) is also gas. I dont know if there is much out there in a modern diesel that would be much more efficient at 1-row cultivating than that little old 10 hp Farmall. I also use that tractor on a snowplow in the winter for light snows, or when I want to get out of the house for a little longer than I could on my larger diesel, which always makes very short work of my driveways no matter how deep the snow. A problem with my diesel (JD 4120) in the winter, is if the block heater is not plugged in for at least 30 minutes, cold starts are rough, with about 2 minutes of rattly, smoky operation before things smooth out. The little Cub, with its spark plugs, is ready to go on the second crank of the engine, as is my 1951 Ford 8n, no matter how cold it is. I have yet to see any diesel engine that was very happy starting when real cold, but I have only seen one gas tractor that wasnt. That would be my crank-start, 1942 Allis Chalmers C, which simply refuses to fire when the temperature is below 45 degrees F. No problem though, because I only use it when it is warm out. I like having a crank-start tractor that dont need a battery as those can be trouble at times, particularly if the tractor is kept at a remote location. A diesel would be very difficult to crank over by hand due to the high compression. My 8 year old daughter can almost crank start that old Allis. Other advantages to the gas tractors is more widespread availability of fuel and lower cost per gallon (these days anyhow).