Is the intake manifold of the old Jetta engine good or not?

1, power. Because the inner wall of the intake manifold of plastic engine is smooth, it is beneficial to improve the intake charge. Compared with aluminum alloy intake manifold, the engine power can be increased by 3% ~ 5%.

2. It is made of plastic, in order to reduce the weight of the engine, make the plane more stable and increase the air intake.