Crazy Clem is correct. Diesel oil has an additive blend that is designed for diesels. It deals with sooting, fuel dilution, higher pressure and higher heat much better.
I would just watch running stabilizer of any sort and verify what your getting in any additional additive package. Most are fine but some can cause internal damage and adverse affects on the ability of the oil to create the high pressure layer. (slick 50
) I personally dont run any additives but thats not to say theres anything wrong with them. Blackstone does an analysis that can get you an idea of where your current oil lacks and gains.
I've never seen a 30W in a diesel based package in this area but thats not to say they dont make it.