Rislone oil treatment is a high-viscosity formula developed for older and higher mileage engines to increase oil film thickness, building a thicker oil cushion and increasing oil pressure in worn engines. Cushions and coats engine parts to reduce friction and wear by preventing metal-to-metal contact between moving parts, giving your vehicle longer engine life. Increased oil pressure equals increased power and a quieter running engine. Improved high-performance formula performs better in both hot and cold weather. Works with all gasoline and diesel engines using conventional high-mileage and synthetic oil. Use in any 4, 6, and 8 cylinder car, truck, van, or SUV. Rislone oil treatment may be used anytime, at or between oil changes. 1 bottle treats 4 to 5 quarts of oil.