My 318 got changed from Type F to low-viscosity Hygard, which is Deere's current recommendation.
That plus a new filter when I first got the tractor. It's about due for another oil and filter change. I bought a 5-gallon pail of low-viscosity Hygard when the 2nd-before-last local Deere dealer had it on sale, so that's what I'll refill it with.
Hank