Lucas Engine Break-In Oil Additive is an exclusive blend of extreme pressure additives that protects camshaft, lifters and valve train during the engines break-in period. In fact, it is excellent for flat tappet camshafts during break-in or as an additive to prevent premature wear. Additive can be used with any motor oil, conventional or synthetic. Designed for race applications that require additional extreme pressure additives. Dyno testing shows a more efficient break-in when this additive is used, resulting in less engine run time prior to race day. One bottle can also be used with every oil change to increase the zinc content of your motor oil.