The main difference is in the ability to cool the fluid. The tube-and-fin style has a tube that carries the transmission fluid through the cooler. It is also distinguished by its turbulators, which agitate the fluid to get more of it to contact the aluminum in the tube. Aluminum fins are attached to the outside of the tube and, since aluminum dissipates heat quickly, the heat from the fluid is absorbed by the aluminum, moves out to the fins, and is then carried away from the cooler by the air flowing through the fins on the outside of the cooler. This style of cooler works well but is the least efficient type of cooler that we carry.
Plate-and-fin coolers work on the same principle as the tube-and-fin-style coolers but are more efficient. Plate-and-fin coolers force fluid through much smaller plates that, like the tube-and-fin cooler, cause turbulation (or agitation) of the fluid. But fluid in the plate-and-fin style is cooled better before leaving the cooler because the smaller, flatter plates allow more fluid to contact the aluminum surface inside the cooler.
Stacked-plate coolers are the most efficient coolers. They have the same design as the plate-and-fin style, but they have high-flow turbulators for heavy-duty towing or race applications. The stacked-plate design uses AN (Army-Navy) fittings, which are popular in high-performance and racing applications where the cooler may need to be installed and removed more frequently than in a typical towing setup.