E-mailed cummins and asked if it was ok to use oil that contained moly(penz or bobsoil) in my b5.9 engine(dodge ram) They said "Moly can be aggressive to the copper in bushings/bearings". Looks like i will still use the proven, reliable, Rotella T. Funny though they did put in a plug for Valvoline premium blue. Well i thought moly was the way to go but looks like i will have to stick to no moly oil. HMMM wonder what navistar and isuzu say about moly.