That guy does not have the first clue on how to test a tractor transmission oil. Try to forget you ever saw that video.
Kubota SUDT2 has two properties that distinguish it from standard formulations.
- It has a slightly lower viscosity of 8.1 cSt @ 100C (KV100) and a very high viscosity index of 199. Conventional formulations which include regular UDT have a KV100 around 9.5 and a viscosity index of 135. That allows SUDT2 to flow better in extremely cold weather. Very analagous to a 0Wxx versus 10Wxx engine oil.
- SUDT2 can absorb more free water than standard formulations. That helps prevent the formation of emulsions, sludge, and additive dropout that can clog filters.
Wear wise ALL of the products "tested" in that video are Gl-4 level gear oils.
In summary, SUDT2 is a superior performer in cold weather and rice paddies neither of which are common in your locale. Its a little colder here in MD and I use it in my HST tractors for the same reason I use 0W40 engine oil.
My old B7200DT lived a long and happy life on Travellers Premium UTTO. Given the rate at which my G2160 has started puking SUDT2 it may soon get switched to the much less expensive brew.
Dan