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SAE transmission oil viscosity grades

Viscosity Classification of Lubricants For Axles And Manual Transmissions

The viscosity of automotive manual transmission oils is described by SAE (Society of Automotive Engineers) viscosity grades. SAE J306 standards set: the temperature of viscosity measurement, viscosity limits and the distribution of viscosity grades. Oils for which viscosity limits are set in the cold state have an additional letter W (Winter). Seasonal and multigrade gear oils are available. Modern multistage gearboxes require all-season oils with a wide viscosity range of SAE 75W-90 or SAE 75W-80. For hypoid main gears, viscosity grades from SAE 75W to SAE 85W-140 are recommended.

Viscosity Grades SAE J306

SAE Grade
Maximum temperature, оС at viscosity 150000 mPa·s Kinematic viscosity, mm2/s at 100 оС Kinematic viscosity,  mm2/s at 100 оС after 20 hours KRL test (CRC L-45-T-93), min
min max
70W -55 4,1 4,1
75W -40 4,1 4,1
80W -26 7,0 7,0
85W -12 11,0 11,0
80 7,0 <11,0 7,0
85 11,0 <13,5 11,0
90 13,5 <18,5 13,5
110 18,5 <24,0 18,5
140 24,0 <32,5 24,0
190 32,5 <41,0 32,5
250 41,0 41,0