Castrol RX Super 15W-40 CJ-4/E9 is an advanced heavy duty diesel engine oil. It is suitable for use in high speed 4-stroke diesel engines that use a broad range of fuel qualities. It is compatible with diesel engines fitted with EGR and the latest exhaust after treatment systems such as; DPF, DOC and/or SCR.

Recommended for use in all naturally aspirated and turbocharged diesel engines fitted in trucks, tractors, buses, LCV's and off-highway equipment, agricultural and fixed plant machinery.

New and advanced Castrol RX Super 15W-40 CJ-4/E9 with specially engineered DuraShield(tm) boosters delivers 40% better wear protection*. One of the main causes of damage in modern engines is abrasive wear. Castrol RX Super 15W-40 CJ-4/E9 with DuraShield(tm) boosters is proven in industry testing to provide protection to your engine in two ways:
- Under severe engine operating conditions, soot can agglomerate to form large particles which displace oil on moving metal surfaces. This results in metal to metal contact. Castrol RX Super 15W-40 CJ-4/ E9 with DuraShield(tm) boosters helps to prevent the agglomeration of soot as well as protecting surfaces from wear
- Castrol RX Super 15W-40 CJ-4/E9 with DuraShield(tm) boosters provides a protective layer on the moving metal surfaces which resists break down even under difficult conditions.