Q: Is a plastic or metal intake tube better?
A: Air intake kits are a popular performance upgrade. They are affordable, easy to install, and provide noticeable gains over a stock intake.
However, there are many choices. One major difference can be the shape and material of the tubes.
Many intake kits are available with aluminum or steel tubes. They are also available in various finishes. The tube could be painted, polished, powder-coated, or even chrome.
Another popular option is a kit with polyethylene (or another plastic) tubes. Most of these tubes are black in color. Some tubes might also have a logo or brand name on them.
Other Types of Tubes
So, which one is better?
There is a common belief that metal tubes hold more heat which raises the temperature of the intake air. Therefore, plastic tubes would be preferred because cold air makes more power.
The temperature theory is not wrong necessarily.
However, the temperature difference is so small that, in most cases, it won’t actually make a difference.
The reason plastic (and rubber, and carbon fiber) tubes are generally better is because of their shape.
Metal tubes are much better than the restrictive factory intake of most vehicles. But, the shape of metal intake tubes is limited as metal tubes can only be bent and welded so much.
Plastic and other materials are molded into shape, offering more design flexibility, and often, a more efficient air path.
Plastic tubes can be made less restrictive than their metal counterparts. This makes it easier for the engine to breathe, which speeds up the incoming air, and can result in your engine making a little more horsepower.