General Motors “Aero X” Experimental Aerodynamic Car

General Motors – Vauxhall's parent company in the US – has unveiled a new experimental aerodynamic concept car, called the “Aero X”.

Irwin W. Rybicki, GM vice president in charge of the Design Staff in Detroit, said, “The 'Aero X' represents the latest example of the aerodynamic studies which are a normal part of our look into the future. These studies indicate that efficient cars can be designed without sacrificing aesthetics of comfort. We consider the 'Aero X' a step along the path of product improvement which we intend to pursue vigorously.”

The “Aero X” is a full-size vehicle concept, designed to carry four passengers in comfort. It is a glass fibre prototype which has been carefully tested in a wind tunnel in both reduced scale and full size. It gets its name from the fact that it is designed around GM's highly successful “X” car, marketed in the US as the Chevrolet Citation, Pontiac Phoenix, Oldsmobile Omega and Buick Skylark.

The bonnet of the “Aero X” slopes in a gentle curve, and cooling air is admitted to the engine through a unique “under the nose” inlet. The headlights are retractable.

A smooth transition from bonnet line to windscreen improves air flow over the upper body. Flush glass is used all around the car, with body pillars set behind the glass. Wipers are recessed. The are no exterior mouldings. Wheel covers are flush with the wheels, which hare mounted in line with the body to give the car a completely “slippery” configuration.

The rear body form is also shaped so that air flows smoothly over it.

The car underbody – from air inlet back to the front axle – is carefully shaped. A pair of progressively-widening, wedge forms begin under the nose and reach their maximum width at the front of each wheel opening. This ensures that the air flow which is not needed for engine cooling is deflected efficiently under the car.

Aerodynamic tests shown that the wheelhouse space usually required for wheel movements in bumps and turns, contributes to overall drag. In the “Aero X”, each wheel opening incorporates a unique, flexible spacer which smooths the airflow along the entire body side and permits all necessary wheel motions.

The sleek overall design is nearly two inches lower that the average “X” car, and shoulder room is the same as in the “X” car. This result is a six per cent reduction in the frontal area. At this stage of development the “Aero X” has a drag coefficient of .285 (as determined from measurements in the new GM Engineering Staff Aerodynamic Laboratory). This coefficient is 40 per cent better that the already .45 of typical “X” body, and compares with the drag coefficient of .38 for the new Vauxhall Cavalier saloon.

This reduction has the potential to improve the fuel economy rating of the “Aero X” by 4 mpg over 1981 production “X” car for the US Government combined city and highway driving schedule. To obtain an equivalent improvement in fuel economy by weight reduction alone, some 500 lbs would have to be removed from the current “X” cars. This could mean extensive use of expensive, lightweight materials. It might also require changes in manufacturing methods.

“The 'Aero X' is an experimental concept that utilises  technology still under development and cannot be converted into a production car overnight”, Mr. Rybicki explains, “but it does represent the continuing efforts of General Motors to offer” better products to its customers.

He concluded, “Our work is never finished. The fact that we have succeeded in dramatically reducing the aerodynamic drag of this experimental vehicle only points to the diligent effort ahead of us. This project illustrates the product improvement that can result when Engineering Staff and Design Staff personnel work together as problem-solving team.”

source: General Motors. Please mention www.allcarindex.com when using this text.

Engine & performance:

Type: Chevrolet Citation, 4-cylinder
Capacity: 2471 cc
Power: 85 hp @ 4000 rpm
Torque: 170 Nm @ 2400 rpm
Drive: FWD

Dimensions:

Length: 4500 mm
Height: 1300 mm
Wheelbase: 2665 mm