Excessive oil burning and exhaust smoking can appear in older, worn engines. Oil burning and smoking occurs when motor oil enters the combustion chamber and is burned along with fuel. This condition, known as oil blow-by often results when friction and metal-to-metal contact have worn parts and created gaps between the cylinder walls, piston rings and valve guide seals. STP Smoke Treatment provides a thicker oil cushion to help fill these gaps and reduce oil blow-by and smoking. Since the oil cushion is thicker, STP Smoke Treatment helps: Reduce oil consumption & smoking. Cushion noisy valves & lifters. Reduce engine wear.