The stacked plate oil cooler has a first plate and a second plate. Both the first plate and the second plate are made of a three-layered aluminum alloy clad sheet. The second plate is folded at an outer rim to place the brazing material layer on both sides of the second plate. The first and second plates and are stacked alternately and brazed to define a water passage between sacrificial layers and, and to define an oil passage between brazing material layers. The first plate is folded at an outer rim to place the sacrificial layer on a lateral outside of a core assembly to decrease exposure of the brazing material layer to the lateral outside.