Presenting a brand new approach to heat exchangers for engines, transmissions, hydraulic systems, etc.This new heat exchanger is made of only two pieces of circular extruded aluminum profiles: Core and shell. No soldering: The core and the shell is assembled by a minimum of automated work.In an oil to water cooling application, the active surface on the oil side of the core is enlarged by fins 0.2 mm thick, 0.3 mm spacing, and 3 mm high. The fins are made in unique production machines and enlarge the active surface area approximately five times compared to a conventional heat exchanger of the same dimensions.The principle utilizes the low pressure drop at laminar flow and avoids the disadvantage of low heat transfer after a certain laminar flow length. The result is approximately three times higher oil heat dissipation, combined with very low oil pressure drop, compared to conventional technique.The inner surface of the core, the water side, is extremely tolerant to dirty water and gives negligible pressure drop.This new heat exchanger is made of only one metal, aluminum. The characteristics of corrosion are therefore easy to define.