Rockfish71

Mobil delvac 1300 super 15w 40 in the boat and in my Diesel truck $12.96 a gal @ walle world.

keith2500hd

due to epa they have removed additive package for auto oil that took load cycles(ZDDP). diesel oil has due to service of diesel engines, marine oil adds corrosion additives to diesel oil.

onesickpantera

iTrader: (1)

This is my understanding as well as well as some motorcylce oil also having higher zddp.

apollard

They took the ZDDP out of most diesel oils now, as diesels now have catalytic converters.

JRider

iTrader: (1)

I am on the same page as you. I run Rotella 15w 40 in my truck and boat. I get some fuel intrusion in both truck and boat engines. Why spend the money on synthetics when I change the oil in such small intervals? In the boat I add stp for the ZDDP