Originally Posted By: tommygunn
No, because ILSAC is only for xw30 and below.
40-wt and heavier cannot be ILSAC
was going to make that point also...t.here was a gf on m1 0w40 in oz a long long time ago, but aun't no way thst a 20w40 is going to provide fuel savings over the reference oils
As others have noted, this is an grade largely replaced by 15W-40.
You will see 20W-40 for marine applications, although I'm not sure why these oils aren't also 15W-40s these days.