Castrol 6140 GTX ULTRACLEAN 5W-20 Motor Oil, 1 Quart, 6 Pack Castrol GTX ULTRACLEAN with its proprietary sludge buster - is our cleanest GTX ever 50% superior sludge protection compared to tough industry standards* Advanced protection against viscosity and thermal breakdown Superior protection against high-temperature deposits Premium quality base oils and anti-wear additives that help extend the life of your engine API SN/SM/SL/SJ; ILSAC GF-5/GF-4/GF-3; Meets Ford WSS-M2C945-A, WSS-M2C930-A, WSS-M2C153-H Castrol recommends the use of Bosch oil filters