To Preserve the life of racing, domestic and collector car engines with flat tappet cam motors. Z Plus's Richard Clark has collected numerous brands marketing similar additives and has analyzed them and determined NONE have the proper amount of ZDDP in it for a normal five-quart engine requiring API SF spec oil. ZDDPlus™ is a surface modifier. It modifies bearing and journal surface characteristics to prevent metal-to-metal contact. Under the right conditions of heat and pressure, the zinc in the ZDDP actually plates over the contact surface and provides a sacrificial coating. As it breaks down, it dissipates back into the oil solution and remains in suspension until the right conditions arise and the process starts over again. This reduces the tendency of parts to scuff and gall under heavy-loaded boundary lubrication situations