M1 0w-40 is not an energy conserving oil. I think you are correct in that it will yield a very slightly lower fuel consumption than M1 15W-50. Not sure if this difference will noticiable however.
Having said that, the 15W-50 used to be an approved oil and factory fill until 0-40 came out.
I think either oil is quite fine. If it were me and I was in Texas, I would use the 15W-50 to handle the wretched heat you all get there.
__________________
Rich Belloff
|
Threaded Mode
