Castrol GTX is one of the world’s most trusted engine oils.;It's more than just oil. It’s liquid engineering that protects against the problems your engine faces every day. Severe driving conditions can cause the build up of a thick, tar-like substance called sludge. Sludge can block your engine’s vital oilways like cholesterol – and if untreated it can rob an engine of power and, ultimately, its life.;Castrol GTX Double Action formula cleans away old sludge*, and protects against new sludge formation better than tough industry standards Help extend the life of your engine with Castrol GTX. Castrol GTX 5W-40 C3 provides;Provides superior protection against engine sludge*;Advanced protection against viscosity and thermal breakdown.;Premium quality base oils and anti wear additives to help extend the life of your engine.;Helps minimize oil consumption Protects emissions control equipment like Diesel Particulate Filters;*Vs API SN Limits/ACEA C3 Industry Standards.