Wynn’s® Diesel Clean OSC is a premium product formulated to chemically clean and condition the engine crankcase during an oil change. Wynn’s® Diesel Clean OSC safely dissolves sludge, varnish and oxidized oil deposits decreasing the soot load in the crankcase and increasing the viscosity index of the new engine oil. As oil ages, its ability to protect the engine declines. A conventional oil change leaves contamination behind, compromising the ability of the new oil to transfer heat, lubricate and protect critical engine components. Wynn’s® Diesel Clean OSC leaves your system cleaner than an oil change alone and gives your oil the fresh start it needs to keep your engine running its best.