NVH performance of convertible-fuel vehicle

The NVH performances of JETTA convertible-fuel car using gasoline or liquefied petroleum gas (LPG) as fuel were experimentally investigated. The vibration levels of the engine block and the driver seat as well as the interior noise level of the car and under the engine hood were measured at constant speed as well as the uniform acceleration of the car and uniform acceleration of the engine with the standing car respectively. The test results showed that at constant speed the engine block vibration of the engine using LPG is lower than that using gasoline, but the noise level of LPG fuel is higher than that of gasoline. When the car is accelerating, the noise level corresponding gasoline is higher than LPG at low engine speed, but the result is reversed at high engine speed.