Castrol Vecton 15W-40 CJ-4 is an advanced engine oil, formulated with unique System 5 TechnologyTM for up to 40% better performance. Castrol Vecton 15W-40 CJ-4 is designed for the latest US and European diesel engines with modern exhaust emission control systems, including DPFs. It is suitable for extended drain intervals in both on-road and off-road applications.