Thermoplastics and fiber-reinforced thermoplastics have lower production costs, but poor impact performance, and there may be a cracking of the imported pressure reducing valve under dynamic load. The part with high plastic penetration rate around the engine is the intake manifold. PA is the material for plastic intake manifold. In 1998, more than 80 vehicles produced in Europe and North America will use PA intake manifold. In the next 10 years, the amount of PA used for intake manifold will increase the force port by 18kT.

The main advantages of plastic intake manifold are lower cost and lighter weight. In addition, because PA has lower thermal conductivity than aluminum, fuel nozzles and incoming air temperatures can be lower. Not only can improve the emergency solenoid valve thermal start performance, but also improve the power and torque of the engine, and the plastic intake manifold wall is more smooth, safety solenoid valve can reduce air flow resistance, so as to improve engine performance.

The first plastic intake manifold to be commercialized was made of unsaturated polyester BMC in Frudenberg, Germany, using the "IOstmetal" molding process. The inner surface of the made manifold is very smooth, which helps air flow, and the power of the engine is 15% higher than that of the metal manifold, and the weight of the manifold is reduced by 1kg.

Rogers uses a ductile, fatigue resistant alloyed plastic (XB-22) for a 30% reduction in mass, reduced manufacturing time and reduced noise.

The plastic intake manifold, developed by GENERAL Electric plastics in collaboration with CMI International, is made of fiberglass reinforced PPS and PA alloys with other engineering plastics. Tests show that its durability is higher than or equal to aluminum manifolds, and its inner surface is smooth and light. Another advantage is the lower thermal conductivity of plastics and the higher density of air at low temperatures, thus improving the air-fuel ratio and thus the efficiency of the engine.

The intake manifold of the Chrysler twin-overhead camshaft 2.0L engine is made of DuPont material produced by investment casting. Although the newer twin-overhead camshaft variant is touted as a cast aluminum engine, it is a testament to the gradual introduction of plastic into the manifold area.