1984 Chevrolet Citation IV Concept
The Product of Good Stock
The Citation IV didn’t show up on the concept scene entirely fresh. In fact, it is essentially a functioning clone of one its progenitors.
Its roots are arguably grounded in at least three concept cars that preceded it, all of which were released not with Chevrolet bowties but rather the General Motors name. Starting in 1981, the “Aero X” was introduced, followed by the “Aero 2000” in 1982, and the “Aero 2002” in 1983. Each of these concepts was a full-sized model but not drivable.
Although the Citation IV’s shape is merely hinted at in the four-door Aero X, and the two aren’t likely to be confused, they do share certain traits. For example, flush glass and door handles, a grill-less front with under-the-bumper air inlets for engine cooling, and wheels positioned outward, flush with the body panels. Those forward-thinking features and more would be passed along to the Citation IV. (For more information on the Aero X, click here.)
The Aero 2000 eliminated outside mirrors and any indication that windshield wipers were intended. Although the Aero 2000 employed pop-up headlights like the Aero X, the Aero 2000’s nose was more rounded and its windshield more swept back, clearly influencing the Citation IV’s design. The Aero 2000’s interior, while proposing some questionable ideas, also began to point towards Citation IV with slim-design seating and digital instrumentation that included a cutting edge heads-up display. (For more information on the Aero 2000, click here.)
It’s in the Aero 2002 that the Citation IV’s family ties can be clearly be seen. The Aero 2002 incorporated what would sometimes be referred to on the Citation IV as a “beaver tail” rear end. While possibly not visually appealing to some, the design feature was critical in reducing turbulence at the car’s trailing edge. Like the Aero 2000 before it, the Aero 2002 was still designed with pop-up headlights in mind and used wheel skirts that covered nearly half of all four openings. One of the few visual differences from the Citation IV were the body-colored vents on top of the hood apparently intended to offer air extraction from the engine compartment.
Through testing in wind tunnels, engineers would determine a car’s Cd value which is a measurement of a shape’s resistance to air (lower values are better). Interesting design aside, the Aero 2002’s claim to fame would have to be its 0.14 Cd. This was a new record for GM designers for a vehicle of that size. (For more information on the Aero 2002, click here.)
Putting Things In Perspective
How does the Aero 2002 concept’s 0.14 Cd compare to modern day aerodynamic designs? For comparison, running an ultra-efficient Chevrolet Volt through the wind tunnel will net a 0.28 Cd, twice as much resistance. How about a modern (C6) Corvette? Also rated at 0.28 Cd, in its most slippery guise.
In Volt’s and Corvette’s defense, they are production vehicles and the Aero 2002 didn’t even have an engine–meaning, it was designed with few engineering constraints. Further, there are other factors that affect aerodynamics besides shape-specific Cd ratings (for example, the size of the vehicle). Generally speaking, however, the Aero 2002 was and still is an incredibly low-drag design.