モトーリ・モデルニ
Following the poor 1989 season, Enzo Coloni struck a deal with Subaru prior to the 1990 season to become the Japanese manufacturer's works team. This deal, where Subaru bought half of the Coloni team, meant that the Cosworth DFR was replaced by Subaru's 1235 flat-12 engine. This engine, which was of Subaru's typical boxer format, was developed by Motori Moderni, and had originally been intended for Minardi. However, the engine was not a noticeable improvement over the DFR; it only produced a modest , with Motori Moderni targeting a power output of , and it was also overweight, weighing . Although this was only heavier than the old DFR, the complete engine assembly was actually . To make matters worse, it would also prove to be unreliable, and prone to failure. The engine was designed to use a Minardi gearbox. The C3 was updated to the C3B specification in order to accommodate the new engine, and was actually quite a major change; for example, the airbox was removed, and replaced by two sidepod-mounted air ducts, which led to the sidepods being taller and longer. The weight of the Subaru engine also caused the C3B to have somewhat unpredictable handling, as the weight balance was quite heavily centred towards the rear of the car.