The Opel Tech I was a concept car shown by Opel at the IAA motor show, built to demonstrate practical aerodynamic engineering rather than an extreme or unrealistic design exercise. It was developed using the running gear of the front-wheel-drive Opel Kadett, reflecting Opel's aim to base the study on componentry typical of the lower-medium class, a segment that represented about a third of the European car market at the time.
The body was a five-door fastback saloon with seating for four. Wind tunnel testing at Pininfarina produced a drag coefficient of between 0.235 and 0.245. The car's flanks were shaped for optimal airflow and it featured a tall tail section that helped keep air attached around the rear window, an approach later widely adopted in production cars. Glazing was mounted flush with the body and extended over the roof pillars to aid aerodynamics, while a coupe-like seating position reduced frontal area, prompting Opel's designers to describe the car as a four-door coupe with a tailgate, drawing a design parallel with the Opel Manta. The alloy wheels were developed jointly with ATS to limit turbulence without compromising brake cooling.
The front air intake could be adjusted in cross-section according to the engine and gearbox combination fitted, improving the drag figure by limiting intake airflow to what was needed. Underbody paneling and a rear spoiler further aided airflow and reduced dirt buildup. A ribbed white acrylic panel between the tailgate and bumper concealed the rear lights when off and hid the license plate mount. Inside, an electronic instrument panel displayed only information relevant to the current driving situation, with additional readouts available on demand. The front-end styling of the Tech I anticipated aspects of the Opel Omega, which arrived five years later.
