I am about to finish my second Auto-Rx clean since new, on my 01 PSD. After using different oils in this engine, including full synthetic, and looking at the analysis, the best one was with the Schaeffers 15W40. So I am going to change back to this oil for the duration of my ownership.
My 95 PSD has been run the last 14 months on Royal Purple. The analysis at 12 months was excellent. In my quest for one oil for both trucks, I will be changing this truck back to Schaeffers 15W40 also.
So for me, now it will be easy when I have to order oil, then I can get the $250.00 order and free shipping from Schaeffers.
I have tried the lighter oils in both trucks and they both thrive on the 15W40 oils more than the lighter oils. Seems like less engine noise and less make-up oil is needed.
My 95 PSD has been run the last 14 months on Royal Purple. The analysis at 12 months was excellent. In my quest for one oil for both trucks, I will be changing this truck back to Schaeffers 15W40 also.
So for me, now it will be easy when I have to order oil, then I can get the $250.00 order and free shipping from Schaeffers.
I have tried the lighter oils in both trucks and they both thrive on the 15W40 oils more than the lighter oils. Seems like less engine noise and less make-up oil is needed.