Abstract: An intank oil cooler assembly comprises a plurality of manifold end connected, vertically stacked, elongated tubular panel subassemblies, containing structurally enhancing header manifold connector end post with external circular wide flanges, manifold intermediate spacer disc washers, and a base plate subassembly placed in a supporting bottom base position. Each thin-walled, tubular panel subassembly has header manifold inlet and outlet end sections, an internal central longitudinal flow channel region designed for conducting internal fluid flow, and also, has a turbulizer subassembly installed therein for causing internal fluid turbulization to optimize heat transfer. Each tubular panel subassembly is fabricated by laminating together paired, thin-walled plate elements having sidewalls embossed with dimpled exterior surface projections on their outer convex surface and axially corresponding reverse side dimpled depressions on their inner concave surface.