How Plastic Components Drive Automotive Fuel Efficiency

54.5

That’s the Corporate Average Fuel Economy, or CAFE, that the U.S. government expects all of the country’s cars and light trucks to conform to by 2025. In 2014, the average was 24.1 miles/gallon. The automotive industry is under intense pressure to more than double the average vehicle fuel efficiency in the next decade. The clock is ticking.

In the past 5–7 years, the sector has advanced significantly, with hybrid‑electric and electric vehicles gaining traction. Yet the path to the 54.5‑mpg target will require a convergence of many technologies, including the widespread use of lightweight plastic components.

Plastics already represent roughly 50 % of the materials in today’s cars, yet they account for only about 10 % of a vehicle’s total weight. Reducing weight lessens engine load and directly improves fuel economy.

Here’s how plastic components can accelerate progress toward 54.5 mpg by 2025:

Carbon‑Fiber‑Reinforced Plastic (CFRP)

Historically, engineers relied on metal to meet crash‑worthiness standards because plastics lacked sufficient strength. Today, CFRP offers a breakthrough: it is roughly 10 × stronger and 50 % lighter than steel. The Corvette Stingray’s hood and roof, and the BMW i3’s passenger compartment, showcase mass‑produced vehicles that employ CFRP.

While the material’s cost has been a barrier, automakers are investing heavily in research to develop more economical manufacturing processes. The performance gains—combined with weight reduction—make CFRP a key contributor to future fuel‑efficiency goals.

3D Printing (Additive Manufacturing)

3D printing builds parts layer by layer, typically using plastic. Although still largely a prototyping tool, the technology holds promise for large‑scale production. Companies such as Local Motors envision cars that could be “printed” for as little as $7,000. Because the components are plastic, they would inherently be lighter and more fuel‑efficient.

Beyond hoods, roofs, and interiors, plastics are being explored for chassis elements, engine parts, and full body panels. Each substitution reduces overall vehicle mass and enhances efficiency.

With 2025 just under ten years away, the automotive industry has a long road ahead to reach the 54.5‑mpg target. Lightweight plastics and advanced composites like CFRP are poised to play a pivotal role.

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