Royal Purple Break-in Oil Engine builders using flat-tappet cams have grown increasingly concerned that many modern motor oils do not provide adequate wear protection for new engines, particularly those using flat-tappet cams. Royal Purple has addressed this issue by developing a new engine break-in oil. Royal Purple Break-in Oil is formulated to allow optimal ring seal and protect rotating assembly components such as the camshaft and valve train from initial start up wear. Royal Purple combines highly refined mineral oil, preferred for engine break-in, with advanced additives containing high levels of zinc and phosphorus to optimize protection in flat-tappet and roller engines. Royal Purple Break-in Oil is fully formulated and does not require the use of any other chemical additives. Royal Purple recommends using their high performance motor oils after the engine is broken in for maximum engine performance.