Vehicle heating device, comprising: - a burner area with a combustion chamber enclosed by a combustion chamber circumferential wall, - a flame tube with a first flame tube end adjoining the combustion chamber circumferential wall or/and providing at least a part of the combustion chamber circumferential wall and with a second flame tube end open in the direction of a flame tube longitudinal axis for the discharge of combustion waste gas, - a heat exchanger housing formed as a metal cast component with a heat exchanger housing circumferential wall enclosing the flame tube on the outside and with a heat exchanger housing bottom located axially opposite the second flame tube end, wherein a waste gas backflow space with an inlet area at the second flame tube end and with an outlet area in the area of the first flame tube end is formed between an outer side of the flame tube and an inner side of the heat exchanger housing circumferential wall, wherein on the inner side of the heat exchanger housing circumferential wall, a plurality of heat transfer ribs, which extend in the direction of the flame tube longitudinal axis and extend radially inwards towards the outer side of the flame tube, are provided with apices located opposite the outer side of the flame tube, wherein an inner dimension (r i) of the heat exchanger housing circumferential wall increases in the direction from the inlet area of the waste gas backflow space to the outlet area of the waste gas backflow space, wherein the inner dimension (r i) of the heat exchanger housing circumferential wall essentially increases constantly in the length area thereof, which encloses the flame tube, in the area of the apices of the heat transfer ribs, wherein an outer dimension (r a) of the flame tube increases essentially constantly in the direction from the second flame tube end to the first flame tube end so that a radial distance between the outer side of the flame tube and the inner side of the heat exchanger housing circumferential wall is essentially constant in the direction of the flame tube longitudinal axis, characterized in that the heat exchanger housing circumferential wall comprises at its inner side in wall areas located with a greater distance to the outside of the flame tube than the apices of the heat transfer ribs between heat transfer ribs adjacent in the circumferential direction the same opening angle in relation to the flame tube longitudinal axis as in the apices of the heat transfer ribs. - a burner area with a combustion chamber enclosed by a combustion chamber circumferential wall, - a flame tube with a first flame tube end adjoining the combustion chamber circumferential wall or/and providing at least a part of the combustion chamber circumferential wall and with a second flame tube end open in the direction of a flame tube longitudinal axis for the discharge of combustion waste gas, - a heat exchanger housing formed as a metal cast component with a heat exchanger housing circumferential wall enclosing the flame tube on the outside and with a heat exchanger housing bottom located axially opposite the second flame tube end, wherein a waste gas backflow space with an inlet area at the second flame tube end and with an outlet area in the area of the first flame tube end is formed between an outer side of the flame tube and an inner side of the heat exchanger housing circumferential wall, wherein on the inner side of the heat exchanger housing circumferential wall, a plurality of heat transfer ribs, which extend in the direction of the flame tube longitudinal axis and extend radially inwards towards the outer side of the flame tube, are provided with apices located opposite the outer side of the flame tube, wherein an inner dimension (r i) of the heat exchanger housing circumferential wall increases in the direction from the inlet area of the waste gas backflow space to the outlet area of the waste gas backflow space, wherein the inner dimension (r i) of the heat exchanger housing circumferential wall essentially increases constantly in the length area thereof, which encloses the flame tube, in the area of the apices of the heat transfer ribs, wherein an outer dimension (r a) of the flame tube increases essentially constantly in the direction from the second flame tube end to the first flame tube end so that a radial distance between the outer side of the flame tube and the inner side of the heat exchanger housing circumferential wall is essentially constant in the direction of the flame tube longitudinal axis, characterized in that the heat exchanger housing circumferential wall comprises at its inner side in wall areas located with a greater distance to the outside of the flame tube than the apices of the heat transfer ribs between heat transfer ribs adjacent in the circumferential direction the same opening angle in relation to the flame tube longitudinal axis as in the apices of the heat transfer ribs.