Bob I'm switching my 540 over to synthetic oil and was at Wal mart getting it and was looking for 15-50 but they didn't have it at all. So I called my buddy and ask him about 10-40.. The only Mobil 1 10-40 they had was labeled "High Mileage".. Is there any difference in a High Mileage vs just a regular full sync 10-40???
And why in the Hell is oil so much cheaper at Walmart vs a parts store????