Why don't any auto makers suggest the use of
15W-40 oil? One of my cars 89 Mirage, says it can use 10-30,10-40, and even 20-50 above 60 degrees, why don't they include 15W-40?
15W-40 oil? One of my cars 89 Mirage, says it can use 10-30,10-40, and even 20-50 above 60 degrees, why don't they include 15W-40?