In recent years being environmentally friendly has become an increasingly important issue that there have been some attempts to address. Within the lawn care field there has been a significant progression in environmental awareness, whether by the force of government regulations or by choice. One of the new technologies that was invented in 2006 to help lawn care companies be more environmentally conservative is propane lawn equipment.
Propane powered lawn equipment is significantly more environmentally friendly producing 80% less toxic emissions than diesel or gasoline. Along with this environmental benefit there is also the fact that it can be purchased for less than these alternate fuels.
Propane is significantly cleaner than gasoline or diesel and burning it is expected to extend the life of your lawn mower's engine. There isn't any dirt that can get in the oil which will make it last longer, and the carburetor will likely stay much cleaner. At this point the technology remains relatively new so this cannot be completely verified, but is likely to be the case.
At this point propane mowers are significantly more expensive but if they are going to last longer and be lower maintenance they may be worth the extra money up front. They are the only real available option for commercial lawn care at this point as I wait for them to produce a functional solar powered commercial mower to use for my lawn care business.