Rislone? Engine Treatment Concentrate is high quality penetrating lubrication oil, combined with protective engine additives and special cleaning agents. Its multi-grade formula allows the oil to flow freely and provides protection over a broader temperature range. Sludge and other harmful deposits within engines can alter tolerances, stick rings, cause noisy valves & lifters, and plug oil passages and screens. The unique Rislone formula is designed to penetrate into valve seats, bearing surfaces, piston rings and ring grooves, where sludge and varnish is likely to form. These deposits are gradually removed and held in suspension until they are trapped in the filter or removed with the next oil change. Regular use of Rislone Engine Treatment, with oil and filter changes at the proper intervals, will keep such deposits to a minimum. A cleaner engine is a better lubricated engine with less friction & wear.