RX Plus 15W-40

New and advanced diesel engine oil specially engineered with DuraShield™ Boosters to give up to 40% less wear for longer engine life (based on engine cam wear performance vs API CJ-4 industry limits). 

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 without DPF/DPD exhaust after-treatment devices.


The main causes of damage in diesel engines are abrasive wear, deposits and corrosion.  Castrol RX Plus 15W-40 with DuraShield™ Boosters actively fights the main causes of engine damage to deliver superior protection by:
  • Preventing the agglomeration of soot as well as removing harmful soot particles from metal surfaces.
  • Providing a protective film on the moving metal surface which resists break down even under difficult conditions, maintaining the film layer.
  • Delivering improved deposit and corrosion protection by resisting thermal breakdown of the oil and by neutralising harmful acids.


  • SAE 15W-40
  • API CI-4 Plus/ CI-4
  • Mack EO-N Premium Plus 03
  • Cummins CES 20078
  • Caterpillar ECF-2
  • DDC Power Guard 93K214
  • ACEA E7
  • Volvo VDS-3
  • JASO DH-1
  • RVI RLD-2