HTHS for "normal "duty

[gusgeds]

Hi just a question for our experts. Would there be any difference in measurable wear rates at normal operating temps between a car speced to run 5/20 hths @2.9 and an engine speced to run 5/40/ [email protected] both oils being Gp 3 synthetic and meeting SN spec with both engines operating inside safe working temperatures?

 

[userfriendly]

Until an expert comes along, I'll just say no. A HTHS of 2.9 is on the thick side for a 5W20, and 3,5 the thin side for a 5W40.
For example, my 5W40 Delo 400 is around the 4.1 HTHS mark.

 

[BMWTurboDzl]

Only those who designed the engine in question would truly know that. As a layman IMO there would be no difference. Some high performance engines are spec'd to run 20w up to 40w.

 

[CR94]

Originally Posted by userfriendly
... A HTHS of 2.9 is on the thick side for a 5W20, ...
Yes, practically a 30.

 

[ChrisD46]

Most 5W20 are 2.7

 

[ledslinger]

Originally Posted by CR94
Originally Posted by userfriendly
... A HTHS of 2.9 is on the thick side for a 5W20, ...
Yes, practically a 30.


I think Redline 5W20 HTHS is 2.9, or has been in the past. I'm running it in my 2003 Silverado that calls for 5W30. The oil pressure appears the same as 5W30s I've run in the past.