Max ATF is Royal Purple's do-it-all automatic transmission fluid, and the reason it has a following is the additive package. It runs their Synerlec chemistry, which builds a tougher film on the gears, clutches and bearings than a standard fluid does. In a transmission that means less heat and less wear on the parts that actually fail, plus shifts that stay firm and consistent instead of going lazy as the fluid ages.
The other selling point is coverage. One bottle is rated to replace or top off a long list of factory fluids, including GM Dexron III and VI, Ford Mercon and Mercon V, Chrysler ATF+4, and a range of import specs like Toyota, Honda and Nissan applications. That makes it a handy fluid to keep on the shelf when you are servicing several different vehicles and do not want a separate jug for each one. As always, check your owner's manual for the exact spec your transmission calls for, especially on CVT and dual-clutch units, which want their own dedicated fluid.
Typical uses are a full fluid-and-filter service, a drain-and-fill on a high-mileage automatic, or refilling after a rebuild where you want a stout synthetic going in from day one. It is a 1-quart bottle, so figure how many quarts your pan and converter hold before you order.
