speed , any ill affects from runnin 20w50 for summer and changin back to 10w40 in the cooler weather ? I hate changing viscosity back and forth .

 

is it possible that viscosity might change ...........or be differant from brand A as compared to brand B ?

 

Hi Mike. I am still in California; in Ricmond visiting my dad & sister. I'll be back on Monday. You can run 20W50 in the summer and it won't mess anything up to switch back to 10W40 in the winter. I might do that as well. It get over 100-110 in the summer in the Dallas/Fort Worth area. I was just in Palm Springs, Ca where it was 115 and went to Death Valley where it was 122 degrees! Coming back to Palm Spring seemed cooler. It's 80 here in Ricmond (Nice!).

 

Thanks . We actually got a bit of rain a couple days ago which cooled things off a bit ( for now ) but I do not believe we've seen the last of the hot stuff .

 

No, that is an SAE standard.

 

Got it ......Thanks