Castrol Transmax Axle Long Life 75W-90, formulated with Smooth Drive TechnologyTM, is a full synthetic rear axle fluid. It provides superior protection, especially when driving under stop-start or extreme conditions e.g. towing. This enables smoother axle operation and noise reduction, resulting in a more comfortable drive throughout the lifetime of the vehicle. Specially designed and approved by BMW for use in all BMW final drives fitted with conventional (non limited slip) differentials. It is Castrol’s prime recommendation for final drives in heavy commercial vehicles, and is approved by MAN and ZF.