Alternative diesel-fuels include Fischer-Tropsch (synthetic) fuels, biodiesels, blended fuels, and water emulsified fuels that can be used in a compression ignition (diesel) engine without engine or fuel system modifications. The Non-Road Diesel Engine Emissions Regulation applies to all non-road compression ignition (diesel) engines greater than 25 hp (19kW) regardless of fuel used, except for fee reductions for use of biodiesel.