We have been hit with de-sulfurization TWICE in the last fifteen years, once with the LSD, when they started dying off-road fuel RED, and then recently, with the new ULSD.
The problem with both versions is that the Sulphur, while not being of any real benefit itself, sort of bonds itself with the lubricating elements that used to be in diesel.
Removing the Sulphur, thus removing the lubricants, pretty much makes diesel fuel into a paint thinner.
Especially since the advent of ULSD, there has been a plague of leaking injector-pumps, failing rubber fuel-lines, and failing diaphragm fuel pumps; I don't know the scientifics behind the reasons for this.
In an attempt to combat the wear and tear on things, in summer, I add either one 15-oz bottle of STP engine-oil-additive, or one gallon filtered used oil, to each twenty gallons of diesel.
Starting in late fall, I quit the STP/used-oil, and begin adding 8-ounces of Marvel Mystery Oil and 12-ounces of white-bottle Power-Service to each twenty gallons of diesel.
RED-dyed farm/off-road fuel is permitted to have the old LSD sulphur content; but, in reality, it is too much of a hassle for fuel bulk-plants to store and handle two seperate fuels that do the same thing, so you can bet that the RED farm fuel is exactly the same fuel as the un-dyed ULSD, the only difference being the RED dye and no road tax.
Remember the good old Regular and Premium LEADED gas days ??
When the government made the refineries take the lead out of gas, they made NO provision for older leaded-gas engines; the engine designers had to find metals that could hold up to the lack of lead in the gas; try running an older leaded-gas engine on un-leaded-gas and see how many miles you get before the valve seats/stems erode away.
Unless the valves/seats have already been replaced with the later versions, you won't get far.
It is the same way with the new diesel fuels; they couldn't care less what damages it may do to older engines; they may insinuate that something has been done to compensate for the loss of lubricants, but I am not going to count on it.
