Either choice will meet and exceed your mileage expectations... but the 10w40 would perform marginally better during in climate weather...
Oils are formulated primarily for the engine and not the clutch... so you won't
see much difference between the JASO spec and non JASO spec oils to matter...
Friction Modifiers (FM) are only a small percent of the total oil
product and help the base oil do things that it otherwise could not...
(FM) fall into several basic categories but Moly, Phosphors and
Zinc are the most often used friction modifiers... some FM can be a
friction increaser...
Quote Molakule
Remember, a Friction Modifier (FM) can be a friction reducer, a
friction increaser, or one that controls friction in a specified
manner.
Starting in 1972 I have had a love affair with Huskys...
View attachment 144704