Abstract: An oil cooler for motor vehicles, having an outer tube and an inner tube which is disposed within the outer tube and whose outer surface, together with the inner surface of the outer tube, forms an annular channel, sealed in both ends, for feeding oil to be cooled, from an inlet at first ends of the tubes to an outlet at second ends of the tubes, a means provided in the annular channel for ensuring heat transfer from the passing oil to the surrounding tube walls, and a turbulence-generating means provided on the outer surface of the outer tube for a coolant, in which the oil cooler is submerged, the turbulence-generating means consisting of cup-shaped dimples or bump-like projections formed on the outer surface of the outer tube.