Over the past 10 years, OEMS have lowered the viscosity recommendations for diesel trucks. 0W20 is not uncommon – this isn’t necessarily because it’s a better solution for the engine but because it offers better fuel economyu and, potentially, horsepower.

Lower viscosity fluids typically help improve horsepower output, but there’s a fine balance between making horsepower and maintaining the engine’s life.

Engine Builder editor Greg Jones breaks down common question about oil recommendations for diesel engines depending on vehicle application and use.

This video is sponsored by AMSOIL.