The growing need for improved fuel economy is a global challenge due to continuously tightening environmental regulations targeting lower CO2 emission levels via reduced fuel consumption in vehicles. In order to reach these fuel efficiency targets, it necessitates improvements in vehicle transmission hardware components by applying advanced technologies in design, materials and surface treatments etc., as well as matching lubricant formulations with appropriate additive chemistry.Axle lubricants have a considerable impact on fuel economy. More importantly, they can be tailored to deliver maximum operational efficiency over specific or wide ranges of operating conditions. The proper lubricant technology with well-balanced chemistries can simultaneously realize both fuel economy and hardware protection, which are perceived to have a trade-off relationship.In this study, Isuzu light duty truck axle, which is used in one of the highest selling cab-over vocational trucks in the global market, was tested on a full-scale axle test stand. The test stand was equipped with three electric motors and equipped and axle temperature control system. Two fluids, a commercial fluid of SAE 85W-90 (Fluid-A, Group-I with conventional additive) and the candidate fluid of SAE 75W-90 (Fluid-B, Group-III and the viscosity index improver and the new additive) were compared in this testing.This work describes the impact of fluid’s viscosity grade, friction (or traction) and additive chemistry on axle efficiency and durability performance. Additionally detailed results and analyses of the full-scale axle testing results will be presented.