I have a Ranger p/u with 260,000 miles on a 2.3L engine that runs great, after adding the Lucas Oil Treatment my engine quited down so noticebly that I decided to use other Lucas products. I am a believer. The Upper Cylinder Lubricant has made such a difference in my power, acceleration and towing have all become much easier. I am telling all of my friends, worth the ten dollar investment!