In the tradition of the Hollywood weight loss diet, Audi has revealed how to chop almost 220-pounds from its A5 Coupe with its latest Aluminum Prototype. Based around the A5 Coupe, Audi engineers have swapped steel for advanced aluminium and carbon-fiber construction in the interest of fuel economy, emissions reduction and handling agility.

Considering the fact that cars have been getting heavier due to increased safety features and higher feature specs, only a few car companies have managed to reverse the trend in their own cars.

Taking an existing steel-bodied production car as its basis, the A5 project car clearly demonstrates the benefits of the aluminum Audi Space Frame (ASF) concept. Use of the ASF principle reduces the weight of a car body by at least 40% compared with conventional steel construction, and this shows in a curb weight of 2,888-pounds for the aluminum A5 prototype, versus a total of 3,130-pounds for the equivalent steel-bodied series production model.

The lighter weight means the A5 Coupe Aluminum Prototype powered by a four-cylinder engine offers the same performance of a V-6.

The lightweight design of the test car not only enables a smaller engine to supplement a larger one with no impact on performance and gains in economy and emissions, but also has a knock-on effect on ancillaries such as the brakes and transmission, which can also be reduced in size and weight. It also benefits handling and dynamics thanks to the reduction in unsprung weight.