Business

The 4 Wind-Cheating Sedans That Rewrote the Box Era

By Cody Carlson Autoblog

Updated June 15, 2026 8:15 AM

The box didn't fall in the 1970s, it started losing the fight

The 1970s marked the three-box sedan era's peak, but the decade's pressures were pushing automakers toward an aerodynamic shift. Factors like the 1970s fuel crisis and increased highway speeds prompted engineers to rethink efficiency. A more noticeable visual change didn't arrive until the 1980s, when wind tunnel work began expanding from niche motorsport and luxury applications into mass-market production. Aerodynamic drag subsequently became an increasingly crucial engineering consideration, gradually reshaping mainstream sedan designs. This transition is especially evident with the four cars below.

Citroën CX (1974–1991): The futuristic fastback that broke convention

The Citroën CX is one of the earliest large sedans designed around aerodynamics. Citroën's CX replaced the aging DS and was the company's last car designed completely in-house, as Peugeot's purchase of the brand would occur soon after the model's debut. The CX's flowing lines and Kamm tail slicing the car's back off abruptly were wind tunnel tested before the practice became more standard. Covers were added to the rear wheels to help manage airflow, and the rear hatch glass was concave. Petrolicious notes that CX's aerodynamics allowed water to be swept clear without the use of a rear wiper, and its Cd (coefficient of drag) was almost half of the period's typical American cars at 0.36,according to Autozine. American vehicles commonly had a Cd in the 0.45-0.50 range. The Citroën CX's cutting-edge design would win the European auto journalists' Car Of The Year Award in 1975.

Audi 100 C3 (1982–1991): The mainstream aerodynamic breakthrough

The Audi 100 C3 turned heads by recording the lowest Cd ever for a production sedan at 0.30 for its smoothest base model. This Audi's angular nose confidently sliced through wind resistance, and it pioneered the use of flush-fitting glass as a mass-market aerodynamic solution. The 100 C3's flush-fitting side windows featured glass sitting almost perfectly flat with the surrounding bodywork, reducing turbulence and creating clean aesthetics. Audi also implemented a large underflow cover reducing turbulent drag and lift while quieting the ride. The German automaker has continued making headway in aerodynamics, achieving a 0.21 Cd with its 2024 A6 Sportback e-tron.

Need new tires? Save up to 30% at Tire Rack

Find the perfect tires for your exact vehicle and driving style. Click here to shop all top-tier brands, including Michelin, Bridgestone, and more, directly at Tire Rack.

Mercedes-Benz W124 (1984–1995): Conservative shape, serious aero science

The Mercedes-Benz W124 is a prime example of how aerodynamic progress didn't always require extreme styling. Extensive wind-tunnel refinement led to this Mercedes-Benz being celebrated for its 1984 debut with a 0.29 Cd. Elements like smooth surfaces, an inward-drawn rear end, and a clear spoiler lip on the trunk lid were at the heart of its aerodynamic design. Later models even achieved a 0.26 Cd, and fuel efficiency noticeably improved over the previous W123 series. The 500E W 124 (1991 to 1995) would feature a wider body needing to accommodate a V8 engine, so since it didn't fit down the regular W 124 assembly line, Porsche re-engineered the chassis and assembled it by hand. Despite retaining a boxy profile, the W124 had aerodynamics like a modern car.

Honda Accord (late 1980s-early 1990s aero-focused generations): efficiency goes mainstream

Honda's Accord brought aerodynamic design into affordable mass-market sedans. While aerodynamic design became increasingly familiar every day during the late 1980s and early 1990s via the Accord, Honda had already applied an aerodynamic philosophy to the model from its debut. When the Accord was first released in 1976, Honda said, "Several factors contributed to lower noise levels in addition to aerodynamic design. New V-type engine mounts aided in reducing engine noise, while wind sounds have been cut sharply as a result of a new driprail design and new, U-shaped rubber moldings on the doors."

The third-generation Honda Accord premiered in 1986 and refined the nameplate's aerodynamics through design choices such as a low, sleek exterior with retractable headlights, a sharp, sloping nose, and flush-mounted windows that Audi helped pioneer at scale. This generation also minimized drag through a low beltline, hidden windshield wipers, and integrated bumpers. Starting in 1990, the fourth-generation Accord upped the ante with a distinctive Aero-Wedge body blending the classic wedge's crisp lines with the demands of the time's aerodynamic efficiency. To better manage airflow under the car, designers adopted several aerodynamic ground-effect devices found on 1990s racing cars. For example, the wraparound front air dam minimized drag and front-end lift. The fourth-generation Accord also featured a smooth underside to the trunk floor, along with a high rear deck and an integrated rear deck spoiler.

Final thoughts

The collective shift from boxy utility-driven design to prioritizing aerodynamic efficiency didn't happen overnight. Despite pressures like the 1970s oil crisis reshaping consumer demands, models like the Citroën CX in its early days more closely resembled isolated experiments than mainstream design. Aerodynamic-first manufacturing didn't become the norm in America until the 1980s and early 1990s, through models like the third- and fourth-generation Accord, and Europe/Japan largely beat the U.S. to the punch. Now, aerodynamic thinking is foundational rather than optional, and the four models above are pillars of that foundation.

This story was originally published June 15, 2026 at 7:58 AM.