A fluid conveying tube included in a vehicle cooler comprises on its inside first
and second opposite longitudinal primary heat exchange surfaces, and flow-directing
surface structures which are arranged on the primary surfaces. Each surface structure
comprises a plurality of elongate directing elements projecting from the primary
surfaces. The surface structures are alternatingly arranged on the first and second
primary surfaces in such manner that directing elements, succeeding in the longitudinal
direction of the primary surfaces, are alternatingly arranged on the first and
second primary surfaces and are mutually inclined at a given angle (). Each
surface structure comprises a laterally extending row of mutually parallel directing
elements. Thus an input fluid flow is divided into a number of parallel partial
flows which follow a respective spiral-shaped flow path through the tube, whereby
a high heat exchanging capacity is achieved.