Lucas Oil's 10063 Engine Break In Oil Additive with TB Zinc Plus is a specialized product designed for new motors and those with flat tappet camshafts. This additive is particularly beneficial for race applications, offering enhanced extreme pressure protection and faster break-in times, as confirmed by dyno tests.

Users have praised its effectiveness in seating new rings and protecting valve trains and camshafts during the break-in period. It's also versatile, safe for use with both conventional and synthetic motor oils in any racing situation.

Customer reviews highlight its suitability for older engines and flat tappet cams, with many users reporting positive experiences in breaking in lawn mower engines and classic cars. The additive is noted for its ability to help cylinder walls and rings break in properly, ensuring optimal performance.

While some users appreciate the cost savings compared to local auto parts stores, others mention the convenience of fast service when purchasing online. A few users have expressed satisfaction with its performance in new engines, such as a GMC V8, though they plan to use it only during the initial break-in period due to the zinc content.

Overall, Lucas Oil's Engine Break In Oil Additive is a reliable choice for those looking to enhance engine performance during the critical break-in phase or as a preventive measure against premature wear.