What are the reasons for the sluggish acceleration of Jetta?

[AlexDella]

Jetta's sluggish acceleration can be judged from the following two dimensions. 1. First, you can perform some simple checks, such as whether the wrong fuel was used. If low-grade gasoline was added, it may lead to weak acceleration, resulting in reduced engine power and increased fuel consumption. 2. In addition, we can determine the problem based on other accompanying symptoms of the car. If the exhaust pipe emits smoke, especially black smoke, then the combustion chamber, ignition system, or valves may be faulty; if the exhaust pipe emits blue smoke, it could be that engine oil has entered the combustion chamber, commonly known as burning oil.