To provide a car body lower part structure capable of efficiently exhausting hot air in a floor tunnel without lowering aerodynamic performance.
An interval D8 between an exhaust pipe 16 and a bulkhead 30 on the upper end side in the cross direction of the bulkhead 30 is wider than an interval D7 between the exhaust pipe 16 and the bulkhead 30 on the lower end side in the cross direction of the bulkhead 30 and furthermore, an interval D9 between the floor tunnel 14 and a bulkhead 34 in an exhaust space 36 is wider than the interval D8. Consequently, resistance which an air current W1 receives in a cooling space 32 becomes smaller as going to the upper side, the air current W1 smoothly rises and it is possible to exhaust the hot air from an exhaust part 22 by preventing or effectively restraining residence of the hot air in the cooling space 32 and its back-flow to the side of an intake part 26. Furthermore, the aerodynamic performance when a vehicle 10 travels is not lowered as the exhausted air current W1 is rectified by a fin 42.
Kato Kazunori
Katsuichi Nishimoto
Hiroshi Fukuda