I have a P38 heart in a D2 and a D1 3.9. I only use Penrite oil. My 4.0 D2 with 280k on it was excellent inside with Penrite most of its life. My brother has a 4wd shop and for over 20 years only uses Penrite. I have another brother that is required to use Valvoline in the shop he works in. He only uses Penrite in his own petrol and diesel vehicles. Cheers
Cheers

