Scuderia Coloni, founded in 1983 by former racing driver Enzo Coloni in Passignano sul Trasimeno, had competed in Formula One since 1987. The team's record had been modest — qualifying in just 14 of its first 82 race attempts — but it remained active and sought to find a competitive engine supplier for 1990.
Subaru, the automobile division of Fuji Heavy Industries, approached the partnership as a means of entering Formula One. The Japanese manufacturer took a 51% stake in the Coloni team and commissioned a brand-new flat-12 engine designed by Carlo Chiti, a figure with decades of experience in motor racing engine design. Enzo Coloni remained in an operational role responsible for the team's day-to-day running.
The difficulties became apparent before the season even began. By the opening round in Phoenix, the Subaru flat-12 engine was producing no more than 500 bhp — a figure far below what was then competitive in Formula One's naturally aspirated class. The installation itself was hurried: a handful of mechanics worked on fitting the Subaru engine into a modified version of the existing Coloni C3 chassis, and this work was not completed until the day the FIA began shipping Formula One equipment to Phoenix for the first race.
The car was assembled for the very first time in the pits at Phoenix — its shakedown had taken place in the parking lot of an American supermarket near the circuit. It lacked an airbox, featured unusually wide and long sidepods that departed from contemporary design conventions, and was approximately 300 pounds (140 kg) overweight. Driver Bertrand Gachot — the team's sole entry for the season — described the car in later years as "the most fun" he had driven during his Formula One career, despite its lack of competitiveness.
At no point during the 1990 season did Gachot manage to pre-qualify the Subaru-powered Coloni. Pre-qualifying was then required of several smaller teams before official qualifying sessions began; the threshold the Coloni consistently failed to clear. The car lacked aerodynamic downforce, had insufficient engine power, and received only minimal development during the course of the season.
Behind the scenes, the partnership deteriorated quickly. In May 1990, Subaru removed Enzo Coloni from his role as sporting director in an attempt to improve matters. No improvement followed, and Subaru ultimately decided to withdraw from the project entirely, selling the team back to Enzo Coloni. The handover left Coloni debt-free but without engines or sponsors.
Following Subaru's departure, Coloni arranged a supply of Ford-Cosworth engines prepared by Langford & Peck in time for the German Grand Prix. An updated version of the C3 chassis designated C3C appeared alongside the engine change. The car was faster than the Subaru-engined machine, but still not competitive enough to qualify for any race.
At the close of the 1990 season, Coloni had failed to start a single Grand Prix — the second consecutive year in which the team's efforts produced no race starts. Enzo Coloni sold the team to Italian businessman Andrea Sassetti at the end of 1991, and Sassetti renamed it Andrea Moda Formula for 1992.
The Subaru-Coloni partnership is remembered as one of the most technically ambitious yet practically disastrous engine programs in Formula One. Carlo Chiti's flat-12 design was conceptually distinctive but far from ready for competition. For Subaru, it represented the extent of the manufacturer's direct involvement in Formula One, and the brand has not returned to the championship in any capacity since. The episode is often cited alongside other ill-fated manufacturer entries as an example of the gap between engineering aspiration and racing reality. Enzo Coloni's team itself would go on to a more productive second life under his son Paolo in Formula 3000 and GP2, but the Subaru years mark the low point of the Coloni Formula One chapter.