The 641 was a developed version of its predecessor, the 1989 Ferrari 640, designed by John Barnard. The updated 641 design was overseen by former McLaren designer Steve Nichols after Barnard left Ferrari to join the Benetton team, once the car's development was complete. The car was powered by a 3.5-litre V12 engine, first with the type 036, and later in San Marino with the updated 037. The V12 was rated at , only slightly down on the Honda V10 engines used by McLaren, but not as flexible or as good at delivering power out of slow corners as the Honda, the Renault V10 engine used by Williams or the Ford-Cosworth HB V8 used by Benetton. Despite its heavier engine, the 641 was among the best handling cars on the grid. Prost declared it the best car of the year.