At around 57,000 miles my engine started making a load tapping sound during start ups and would last until the engine would warm up. Fearing that I was in need of major internal engine work, I went to Autozone to see if they had any recommendations. The manager told me that everyone at the store uses Lucas Heavy Duty Oil Stabilizer on their vehicles and that it is known to reduce knocking and tapping sounds in engines. I changed the oil and added the product. Lucas Oil did not reduce the tapping sound, it completely ELIMINATED the noise. It saved me an expensive bill from the mechanic and I will now add it every 3000. I highly recommend this product to anyone.