Engine Flush: (1) Removes harmful sludge and deposits. Protects engine wear surfaces throughout the flush. (2) For petrol and diesel engines. Contains anti-wear additives. (3) Helps maintain efficient oil circulation throughout the entire engine. STP Oil Treatment: (1) Contains Zinc anti-wear agent ZDDP. Lubricates and protects moving engine parts. Reduces oil consumption and burning. (2) Helps protect against engine wear. Help fight metal-to-metal friction by providing a thicker cushion. . .