UDT and HyGard (J20C) are both 10W30 oils as are the vast majority of UTTOs - KV100 around 9.5 cSt, VI north of 140,, and Brookfield viscosity of 70000 cP @ -40C
SUDT2 and low-vis HyGard (J20D) are both 5W20 oils - KV100 around 8 cSt, VI approaching 200, and Brookfield viscosity around 18000...