From the broadly 2 approaches i know of, i see it as where one
incurs the cost as ultimately the overall costs (monetary &
otherwise) can turn out the same.
Those Euro-4 diesels which don't use additives are very fussy on
fuel, they only accept the more expensive lower sulphur diesel,
which also is very limited in supply nowadays & only some fuel
stations stock them.
Majority of diesel fuel (especially in 3rd world) is the cheaper
higher sulphur grade which remains widely available. So a
noteworthy point about those diesel engines which use the additive
approach is that they are less fussy on fuel i.e. they can drink
the cheaper more easily available grade of diesel only that one
needs to stock up on some additives, which only take up a small
proportion in volume compared to the diesel fuel used.
Of course one spend a bit on additives (like buying some extra cans
of motor oil, brake fluid, radiator coolant or even WD-40 etc.)
perhaps keep some always on hand when traveling to more ulu places.
Then just look for the usual diesel station for refilling the
'normal' cheaper diesel instead of being limited by the relatively
fewer low sulphur diesel refueling stations around the world
!
