Composite intake tubes are usually made with a high-density polyethylene plastic. While plastic can sound like a bad word when it comes to auto parts, thermoplastic polyethylene combines lightweight flexibility with outstanding durability. In fact, it can even be found in certain bulletproof vests. This composite material is more than capable of withstanding conditions under the hood of your vehicle.
From a performance standpoint, there are a couple of advantages that composite has over metal. First, composite material doesn’t retain heat the way metal does, meaning your plastic tubing doesn’t run as much risk of heating up the air entering your engine. Second, the composite molding process allows for precisely engineered bends, moreso than can be found on a metal intake. This allows the air to flow more freely to the intake manifold, slightly improving power over a metal tube.