A 20W-50 motor oil is typically used in older vehicles or in particularly warm climates. Castrol GTX 20W-50 has been specially formulated to help extend the life of your engine by keeping it free from sludge, even when operating in extremely high temperatures.
If you need a 15W-40 diesel oil, Castrol GTX helps extend engine life, protecting against the wear and tear of severe weather, rough roads and heavy tows. As a 15W-40 viscosity grade, it flows like a 15 weight oil from start up in Winter, but provides the protection of a 40 weight once the engine reaches full operating temperature.
There are two things you need to know to find the right oil for your vehicle 1) the viscosity, 2) the manufacture specification requirements. The products on this page are all 15W-40 viscosity and also show the manufacturer specifications details.