5W30 vs 5W40 in a GM car

[clarkz71]

Interesting that Chrysler DID recommend a 5W40 back then. Like I told GM customer service, oil technology has advanced in the last 22 years since the Northstar was designed. .

 

[zeng]

Originally Posted By: clarkz71

Interesting that Chrysler DID recommend a 5W40 back then. Like I told GM customer service, oil technology has advanced in the last 22 years since the Northstar was designed. .

+1 Thanks for sharing. Btw, what's your take on my comments above dated 09/06/15 , that Merc/Northstar bearing clearances appears to be on the coarse side

 

[clarkz71]

Originally Posted By: zeng

+1 Thanks for sharing. Btw, what's your take on my comments above dated 09/06/15 , that Merc/Northstar bearing clearances appears to be on the coarse side

Compared to the Asian specs, yes. Compared to high performance domestic V8 engines, no.

 

[zeng]

Originally Posted By: clarkz71

Originally Posted By: zeng

+1 Thanks for sharing. Btw, what's your take on my comments above dated 09/06/15 , that Merc/Northstar bearing clearances appears to be on the coarse side

Compared to the Asian specs, yes. Compared to high performance domestic V8 engines, no.

+1 How about Asian bearing specs (4I) against domestic V6 and 4I , within last 5-10 years production , with 0W-20 as standard oils ?