In Reply to: 90 WT Mineral Oil posted by mthomas on March 28, 2018 at 08:57:40:
Hokie is correct, why look for and pay extra for an inferior product? GL-1 was simply an alternate to the original Mild EP that is the spec for N tractors from the beginning. If you just happened to be around during WWII you would realize how difficult it was to get most any of the lubes or fuels. Also found in N war era specs in addition to SMO you will find 50W motor oil for the hyd and gears. After the war all N's had only Mild EP specified.