Abstract: An exhaust system for a vehicle includes a valve including a valving element movable to a first position upon movement of a portion of the vehicle body to a raised position, whereby exhaust from the vehicle engine is directed to a muffler, while with the portion of the vehicle body in a lowered position and with the valving element moved to a second position, the engine exhaust is directed partially through the muffler, and partially through a member of the body portion. An over-center spring is connected to the valving element to bias it towards its first and second positions whereas a plunger is connected to the valving element to move it to its second position in response to lowering of the vehicle body.