super udt first came about in the l series with gst transmissions. In cold conditiions, below 30 degrees, the gst would not shift due to the small orifices . If you let the unit warm up, it worked allright, but when cold would not. later, on the m series, it became mandatory due to independent pto clutches and wet brakes. If not used in a M series tractor, the brake and pto clutch linings will come apart. $1200. repair. So, if you have wet brakes and independent pto, use super udt, I sell in bulk at $9.94 gallon. Its not worth the difference on your tractor to try to use the "cheap" stuff. As far as I know it is only available at Kubots dealers, although it is made by TROCO oil co. in O.K. hope this helps