What weight oil does a 5.9 Cummins take?
What weight oil does a 5.9 Cummins take? 2003 - 2007 5.9L Cummins ISB Oil Viscosity Chart (24 valve, common rail)Ambient Temperature RangeRecommended Oil ViscosityGreater than 0° FSAE 15W-40All temperaturesSAE 5W-40 full synthetic Can I use 5w30 instead of 5w20 in my Hemi? His shop has been in the same place since 1988. He said 0w30 will help improve lubrication in the 5.7 HEMI. Most who are using 30 weight oil appear to be using 5w30, though some are using 0w40 as well. 5w20 or 5w30 is going to have the same cold temp viscosity, so either one should be...