Poor fuel, heat and tough driving conditions are factors you can’t control that cause sludge, varnish and carbon to form inside your engine, potentially shortening its life. Castrol GTX Ultraclean is our cleanest GTX ever. Its Ultraclean synthetic technology cleans away old sludge, and prevents new dirt from forming 50% better than industry standards.
- 15W-40 API SN/CF
- Superior sludge protection for greater reliability in modern vehicles
- Advanced protection against high temperatures & stresses
- Anti-wear additives extend life of engine
I had to dig into the MSDS trying to find if this is a pure synthetic or semi synthetic and it wasn't easy to find
This oil's MSDS:
https://msdspds.castrol.com/ussds/amersdsf.nsf/Files/8B53F974EB915D4A8025829F0052A540/$File/11356105.pdf
Section 3 states "Highly refined base oil"
Compare to a 0w30 oil's MSDS
https://msdspds.castrol.com/ussds/amersdsf.nsf/Files/014CB64969FCCDEE802580570052A27A/$File/11138348.pdf
where section 3 states "Synthetic base stock"
Any oil chemistry experts able to chime in here? Is it really a "Synthetic"?