A mileage of about 18 thousand km, equipped with 2007 modern Beijing Elantra 1. 6L automatic cars equipped with CVVT engine. User response: the vehicle is insufficient in power and is not well accelerated. After picking up the car, it is found that when the car starts in the air conditioning, the vehicle starts slowly, the engine speed is high, the gear shift is slow, the obvious power shortage appears, and the air conditioning is slightly better after the car is closed.