I don't know anything about sulpher content, but off-road diesel is all I have used since I bought the tractor - close to 90 hours, now. My oil distributor tells me it's the same thing as the on-road diesel, just dyed a different color to indicate that the road taxes have not been paid. I save almost 50 cents a gallon - taxes must be higher, here. I still pay sales tax because I didn't try to qualify as an agriculture operation, but no county or state highway taxes.
My distributor will not deliver for free unless I get at least 300 gallons, so I haul a 55 gallon drum to him for refill. Most of the large farms around here have large tanks, however, and get regular deliveries of off-road. I'm told almost every agriculture and construction implement in the county uses it. I did have to fill out a short form indicating who and where I am and how I will use it. I assume this is so the state can check up on me to be sure I'm not using it in an on-road vehicle. No problem for me; I don't own any diesel powered cars or trucks.