Modern intake manifolds have shifted from traditional aluminum to plastic materials. The primary advantages of plastic intake manifolds are their lower cost and lighter weight. Furthermore, because the polyamide (PA) material has lower thermal conductivity than aluminum, the fuel injectors and incoming air remain at lower temperatures. This not only improves hot-start performance and boosts engine power and torque, but also minimizes heat loss within the manifold during cold starts-thereby accelerating the rise in air temperature. Additionally, the smooth inner walls of plastic intake manifolds reduce airflow resistance, further enhancing engine performance. Regarding costs, while raw material expenses for plastic and aluminum manifolds are comparable, plastic manifolds are produced via a single-step molding process with a high yield of qualified parts; in contrast, aluminum manifolds suffer from low casting yields and high machining costs. Consequently, the production cost of plastic intake manifolds can be 20% to 35% lower than that of aluminum versions.
