I'm currently in the process of planning my initial equipment roster for a part-time solo lawn maintenance operation. Two of my primary goals are to streamline overhead and operational costs as far as possible via equipment efficiencies and to operate my business in an eco-friendly fashion. With this in mind, I'm very interested in the idea of my primary mower being powered by propane. Due to the local availability of propane at bulk fill prices, propane offers me a significant cost savings over gasoline, and the environmental benefits go without saying. I'm also very interested in the 25% or so fuel savings available via EFI technology. Until recently, I was under the impression that EFI was only available in gasoline-powered engines. But after stumbling across the Kohler Command Pro Propane EFI engine which was released in fall of 2012, I realized otherwise. I thought perhaps this new Propane EFI engine would be the ultimate power solution for my new fleet, as it would enable me to combine the operational cost savings of propane with the fuel efficiency of EFI. But from what I have gathered, propane EFI engines are currently only available on one or two ZRT models: ExMark Lazer Z "S" Series ZRT (60"/72" decks) Toro Z Master 5000 ZRT (60/72" decks) These are both larger than my desired deck size of 52", and I have yet to find an EFI Propane engine available in a stand-on ZRT, my desired configuration. I've spoken with Jim Coker at Propane Power Systems, the company which furnishes EPA-approved propane conversion kits for B&S and Vanguard engines. He informed me that no propane conversion kits were currently offered for EFI engines. Are there any additional mower make/models available with propane EFI engines? What about EPA-approved conversion kits compatible with EFI gasoline engines??