While I agree with Vic on temperature and viscosities, SUDT is about how quick it gets there and what it does once there. On the molecular level you are lubricating metal to metal components that are reciprocating, rotating and compressing under great pressures. I have always found in mechanical experience the lubricity of petroleum products are based on friction modifers added to compounds that promote anti-wear and scar resistance formulas to basic organic crudes. ( academic terms for slickness ) The chemical properties of SUDT Vs UDT are all about " slickness '.... now you don't have to be an engineer to understand the value and longetivity of replacing lube oils especially these day when dollars are tight in this Obama economy in the States. Please take the time to learn these terms and then you decide whether or not you want to expose your new B2620 investment to anything less than what the engineers put in it from the factory.....
Kubota Super UDT Fluid
Kubota Super UDT has been developed as per the stringent specifications of Kubota-Japan.
Kubota Super UDT has been formulated using premium base-stocks and optimized chemistry to deliver increased performance and durability.
Low Temperature Fluidity
Kubota evaluates fluid performance in a pump test stand at -30degC.
Improved flow for Super UDT compared to UDT and other commercial tractor hydraulic fluids.
Kubota Super UDT Key Features
Kubota Super UDT provides
Improved hydraulic transmission control
Smoother start of tractor's HST (hydrostatic transmission) at low temperatures
Improved flow through filters during cold temperature start-up.
Less wear on metal parts since Super UDT flows to critical contact areas during start-up.
Reducing Brake Squawk
Kubota evaluates a fluid's performance in SAE #2 machine and low velocity friction test.
Oil "C" is likely to cause squawk in either wet brakes or transmission clutches.
Kubota Super UDT is evaluated with transmission clutch and wet brake friction material.
Stable Friction Performance
Tractor fluids need to maintain friction properties during life of fluid, to insure proper operation of transmission clutches.
Other oil shows deteriorating friction which can lead to poor/harsh shifting, lessened torque transfer and possible wet clutch failure.
Super UDT is improved over previous UDT, offering longer friction stability. Testing is conducted in Kubota's own wet clutch test system.
Kubota Super UDT performance evaluated in the presence of water (0.2%-1.0%)
Super UDT maintains
-Stable friction for clutches
-Smooth gear shifting
-No brake squawk even when water (0.2%) is mixed into
Super UDT will not clog filter even when mixed with 1.0% water. Some fluids form sediment or solids that will clog or block important filters.
Kubota Super UDT features and benefits
No Rust- Reduces wear and tear on equipment
Smooth gear shifts
No brake squawk
Longer equipment life
Improved Shear Ability
Fluid has correct viscosity at high temperature. No metal to metal contact
Less shear of fluid means less power loss in hydraulic pumps
Proper viscosity means proper transmission shifting
Longer equipment life, less down time
Low temperature fluidity
Faster cold weather starts
Less time needed for warm-up
Hydraulics ready to operate with less jerking
Less metal to metal contact
Longer equipment life; less down time
Unique friction characteristics
Smooth gear shifts. Less operator shift shocks
No brake squawk. Less operator fatigue
Maintain brake capacity for safe stopping
Clutches and brake pads last longer
Improved equipment durability