I purchased my 04 F 350 6.0 PSD at 100,000 miles 4 years ago and a buddy who has the same year PSD turned me on to CASE/IH Number one 0w-40 Synthetic. He has been using that in his pickup after the first oil change from new. It is spendy but with winter temps of 25-35 below zero, it starts so easy with the 0w-40. In addition, I use Fleetguard filters for oil and fuel. I realize it is a tractor oil, but after 44,000 miles, it is incredible.
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