Severe driving conditions such as heavy traffic, poor fuel quality, harsh weather conditions, and missing oil change intervals can all contribute to the formation of a thick, tarry substance called sludge. If left untreated, it can rob an engine of its power and, ultimately, its life. This oil is specially designed to prevent harmful sludge buildup, reduce oil deposits and protect your engine every day. To get more miles out of your engine, ask for the right oil from the Castrol® GTX® performance line. Your best miles are ahead with Castrol® GTX®.