Audi Using Aluminum, Carbon Fiber to Drop A5 Weight

In an attempt to create more fuel-efficient vehicles, most automakers are simply building smaller cars that require less gas. Although Audi is increasing its vehicle fuel efficiency with cars like the A3 TDI, it is looking for new alternatives to make more efficient cars without sacrificing performance or size. One such method is to reduce the weight of a vehicle which then allows a smaller engine to be used that can produce the same performance and return better fuel economy numbers. Audi found that weight reduction can be succeeded by using lightweight materials such as aluminum and carbon fiber which can also lead to other changes that improve vehicle dynamics.

To help visualize the improvements, Audi recently took a pair of prototype A5 coupes and replaced the car’s steel with lightweight aluminum (when possible) as well as some carbon fiber treatments, which shaved a total of 242 pounds off the stock A5. Some Audi vehicles (such as the Audi R8, Audi TT and Audi A8) already feature the extensive use of aluminum courtesy of the Audi Space Frame (ASF) that helps reduce vehicle body weight by at least 40 percent. When Audi applied its ASF technology to the prototype A5 models, the weight fell from 3,130 pounds down to 2,888 pounds, which is a reduction of 7 percent alone. In addition to the ASF, Audi replaced steel body panels with aluminum such as the roof and fenders while carbon fiber reinforced plastic panels are used on the hood and decklid.

With such a significant reduction of mass, that means that the A5 can also use smaller brakes and lighter suspension components to reduce the unsprung weight of the vehicle to help improve performance and, more importantly, handling. This also allows Audi to use smaller engines, such as the 2.0 TFSI (2-liter direct-injected and turbocharged inline-4) engine that can offer the same performance figures as the bulkier 3.2 FSI V-6. The smaller engine thus results in improved fuel economy as well signifying the trickle-down effect possible when lightweight materials are used.

Audi is still in the planning phase of using such advanced materials since there are also disadvantages associated with the use of both aluminum and carbon fiber. The biggest hurdle to face is the fact that both materials are more expensive than steel which would equate to higher vehicle production costs. As for carbon fiber, it is not only takes more time and energy to create, but it is also more difficult to recycle. In the end, these prototype vehicles show that it is possible to create more fuel efficient cars without giving up precious performance, but it has yet to be seen wheremanufacturers and consumers are willing tocompromise between the two.

Select photos via Audi