I've been thinking about which way the commercial mower market is going to go in the next decade, and I think based off the rising cost of crude, as well as our more environmentally concerned population, that fuel efficiency and emissions are going to become a large factor in the future of lawn mowers. Therefore I began thinking of what sort of mower drive train would be able to do this. Here are some thoughts just for fun: First off, I think the ideal future drive train will be a hybrid. A gasoline/propane engine (or perhaps biodesial???) that powers a generator. A typical future ZTR will have 3 electric motors. One on each wheel, and a deck power motor. Every other function will be done by servo's and solenoids, completely eliminating the hydraulic system. Power would be by battery packs mounted where the hydro fluid tank would be usually. The mower would operate virtually silent, as you don't need much of a engine to power a generator, and the engine would run through a sophisticated catalyst and muffler. Another thought is perhaps regenerative braking as you slow the mower down to turn it, and perhaps even running off the battery's alone unless it needs to charge, making it even more efficient. The high torque output of electric motors make them excellent to drive wheels and blades. I think a hybrid ZTR would cost several thousand more than a regular ZTR, but with the advantages of extremely better fuel efficiency, almost zero emissions, and low noise pollution, it would pay for itself. Imagine being able to mow at 6 AM without disturbing people? Anyways, just thoughts of mine, feel free to add your ideas.