Triple action, resists wear, deposits and heat No matter how hot, cold, steep, dusty, muddy or extended your operations, you need to know that your oil will protect your engine under all conditions. The Energised Protection of Shell Rimula heavy duty diesel engine oils works relentlessly in three critical areas Acid control, well proven performance additives help to protect against corrosion from acids formed as fuel burns. Deposit control helps to keep the engine clean for consistent performance and long life. Wear control keeps moving metal engine surfaces apart for long engine life.