<p>Coolant radiator for a motor vehicle comprises a radiator component soldered to adjoining cooling ribs (4) and collecting tanks (1, 2). The radiator component is a multifunction flat tube (MFF) having a greater section modulus than an individual flat tube (3). The ends (5) of the multifunction flat tube are connected to the two collecting tanks so that coolant flows through the multifunction flat tube and its fulfills the function of an inner side part of the coolant network and can be used as a filling pipe during filling of the coolant circuit. An Independent claim is also included for an alternative coolant radiator.</p>
