Im looking to purchase a diesel ZTR. Right now Im looking at a used Ferris IS4500Z with 60" deck and a 28hp Cat about 100 hours. Also considering a new Bad Boy 35hp cat 60" deck or a new Toro with the 52" deck 25hp Kubota. Right now, Im leaning towards the Toro since most of the yards are smaller down here in Florida. Any other manufacturers make a 52" deck with a diesel? And since your wondering why diesel, I am currently making my own Biodiesel and it costs me about $1 gallon. So with some basic math, 3000 hours using an estimate of .75 gallons/hr I would use 2250 gallons over the life of the mower. Running Biodiesel I would spend $2250 on fuel versus current USLD #2 diesel costing $10125 IF prices remain at $4.50 for diesel.