Originally Posted by JCH841
The least expensive way to make low sulfer diesel (and therefore the way it is done) is to strip the sulfer out with a hydrogen treatment. This also strips out some beneficial lubricity, so older diesels have excessive injector and valve wear. Newer engines are being designed for low sulfer fuel. (Older gas engines suffered valve seat recession with lead free gas and they designed new valve seats for that.) Caterpillar is pretty much the largest diesel engine manufacturer in the world. I can't imagine them getting out of making diesel engines, not even just over the road or US engines.
Cat is already out of the truck engine business altogether, with the exception of military trucks. But yeah, the low-sulfur explanation doesn't hold water. Their heavy equipment engines are running on it, and their military truck engines are running on JP-8, which is probably even worse. I heard they got out of commercial truck engines simply because of emissions standards. During the last few years they made truck engines, they chose to pay fines rather than meet emissions standards.