Shell Spirax S4 AT 75W-90
Shell Spirax S4 AT 75W-90 is a high-performance part-synthetic automotive gear lubricant developed to provide reliable protection and efficient performance in both gearboxes and axle systems. Formulated with advanced Group III base oil technology and a carefully balanced additive package, the lubricant delivers excellent shear stability, wear protection and corrosion resistance. The oil is designed to maintain stable viscosity across a wide range of operating temperatures, helping ensure consistent lubrication performance in modern drivetrain systems.
One of the key advantages of Shell Spirax S4 AT 75W-90 is its advanced part-synthetic formulation. The use of high-quality Group III base oils provides improved viscosity stability compared with conventional mineral oils. This helps minimise viscosity changes as ambient and operating temperatures fluctuate, ensuring that the lubricant maintains a strong protective film between gear surfaces during both cold start conditions and high-temperature operation.
Shell Spirax S4 AT 75W-90 also delivers excellent protection against wear and gear surface damage. The advanced extreme-pressure and anti-wear additive system helps protect gears and bearings from scuffing, pitting and surface fatigue under heavy loads. By maintaining a durable lubricating film between metal surfaces, the oil helps reduce friction and extend the service life of critical drivetrain components.
Another important benefit of Shell Spirax S4 AT 75W-90 is its ability to improve drivetrain efficiency and support fuel economy. The balanced formulation helps reduce internal friction within gear systems, which can lower power losses during operation. Improved gear efficiency may contribute to reduced energy consumption and improved overall vehicle performance, particularly in modern passenger cars and commercial vehicles.
Shell Spirax S4 AT 75W-90 is also designed to address common operational issues such as cold shifting difficulties and gearbox noise at high operating temperatures. The lubricant’s stable viscosity characteristics help ensure smooth gear engagement during cold start conditions while reducing the risk of “hot rattle” in passenger car and light commercial vehicle gearboxes.
The lubricant is suitable for a wide range of automotive drivetrain applications including heavily loaded axle drives as well as synchronised and non-synchronised gearboxes. It has been developed as a universal driveline lubricant capable of meeting the lubrication requirements of both axles and gearboxes in passenger cars and heavy-duty vehicles. The oil meets industry specifications including API GL-4, GL-5 and MT-1. Physical characteristics include a kinematic viscosity of approximately 92.6 mm²/s at 40°C and 15.4 mm²/s at 100°C with a viscosity index of approximately 177. The oil has a density of approximately 875 kg/m³ at 15°C, a flash point of approximately 170°C and a pour point of approximately –42°C.
