Hi,

I am wondering what people who use M1 are using for oil weights in a moderate climate.
I like the 10-40 but am open to the 15 50 with high miles?

Any thoughts?

 

I use M1 in every vehicle in own, and use whatever the manufacturer recommends.(weight, 5w-30 ect). Engines today are designed different than they were years ago. I remember dad putting only 20w-50 in any car or truck. Engines and even some transmissions are running on much lower viscosity oils for the purpose of getting better milage. IMO run what the manufacture recommends. Plus oils are much better today with synthetics lasting longer between changes.

 

I read the bob the oil guy forums and many who come new are heavy weight fans. The board seems to like as light as possible. They say why not a 70 weight of a 200 weight? LOL
Heavier is not always better.