Motul GEAR COMPETITION 75W-140

Worth knowing

In the Gear line, two synthetic oils on the ESTER Core ester base, with a friction modifier, are aimed at limited-slip differentials: this 75W-140 and GEAR 300 LS 75W-90. The GEAR 300 LS data sheet recommends it where the transmission needs less drag than a grade 140 oil gives, so it is the viscosity grade in the gearbox or axle documentation that decides which of the two to fill.

This oil’s kinematic viscosity is 24.7 mm²/s at 100 °C and 170 mm²/s at 40 °C; for GEAR 300 LS the values are 16.3 and 102.2 mm²/s. The 75W-140 has a pour point of -36 °C, against -45 °C for the 75W-90. The 24.7 mm²/s lies near the lower limit of the band SAE J306 assigns to grade 140 (24.0 to 32.5 mm²/s); according to the data sheet, the oil stays in that grade after the 20-hour KRL shear test. The list of codes differs as well: this one carries only API GL-5, while GEAR 300 LS also lists GL-4. The SAE J306 table in the article on GL-4 and GL-5 gear oil gives every band of the scale, from 70W to 250.