Vehicle heating device

The heater (10) has a passage area formed between an elongated flame tube (16) and a circumferential wall (20) of a heat exchanger housing (18). The passage area is smaller in an outlet peripheral region (48) than a peripheral region (50) located opposite to the outlet peripheral region. The passage area formed in the outlet peripheral region increases in an expansion region (52) in a stepped manner following an axial region (33) and corresponds to the passage area formed in the opposite peripheral region along direction of an exhaust gas outlet (38) in another axial region (35).