sulfur has been what makes it smell so bad...that and the fact that those engines and their commercial use has gone basically unregulated do to their importance in our economy...primarily trucking, bussing and tug and barge traffic.
HOWEVER, with that said, the desulfurizing of the desiel has been implimented with the eventual goal of elemenating it completely....the main problem there being, as with lead in gasoline, the sulphur LUBRICATES those engines internally...without it..they ware at horific rates...hence the reluctance of the industry to change....it's MUCH more expensive.
WHICH in turn reduces their engine life...it cost 200 barrels of oil to build a car...no sure how many it takes to build a huge truck engine, not to mention the boheimiths that go into tug boats...
every from of refuge has it's price.
catman....ISYA
PS...wells are deep...I've just been known to drink a bit after hours, of course !