Ensuring you are Ready for the Road Ahead™, the Shell Rotella® T4 15W-40 Triple Protection Heavy Duty Diesel Engine Oil lends itself as a proprietary Shell synthetic blend formula capable of controlling viscosity and preferred oil pressure levels. Gain control over wear, deposit, oil breakdown, and sludge under extreme engine temperatures for longer engine life. It is imperative to protect your engine against varnish formation, which can lead to parts failure. This heavy duty diesel engine oil defends against oxidation, keeping your truck’s engine in prime condition. FleetPride is your First Click in Heavy Duty®.