Review on High Mileage Engine Treatment: Restore Your Vehicle'S Performance With Rislone 16.9 Oz! by Jay Elmo

I've own a 1995 Subaru Legacy L with hydraulic lifters (later models went to solid lifters). Despite frequent oil changes with good quality oil the valves would tap when the engine was cold. When I put in the Risoline the valve noise immediately went away. I'm not an engineer so I don't know exactly what happened inside the engine to do this. I'm going to drive it awhile to see if stays good.