Mopar 5.7 HEMI Viscosity Varied Recommendations?

[BBDartCA]

Is there any reason, besides fuel economy, for Mopar requiring 5W20 in the Hemi now when just a few years ago it was 5W30? I'm talking about conventional engines, not MDS engines. My 2005 Durango calls for 5W30 while my 2010 Challenger calls for 5W20. Long blocks are the same between the two motors, except I think for cam profile.

 

[zulu]

Best guess is for simplicity.

 

[hounddog]

If you don't have MDS run either.

 

[2oldtommy]

BBDartCA, The reason for the 5w-20 oil spec is that the variable valve timing works off of the oil presure and viscosity. I am told that if you use other than 5w-20, the variable timing will not function as designed. Check out some Dodge Hemi forums for more info. FWIW --Oldtommy

 

[BBDartCA]

Originally Posted By: 2oldtommy
BBDartCA, The reason for the 5w-20 oil spec is that the variable valve timing works off of the oil presure and viscosity. I am told that if you use other than 5w-20, the variable timing will not function as designed. Check out some Dodge Hemi forums for more info. FWIW --Oldtommy


That explains it, thanks.