Among these details was the timeframe for creating the car. Ermanno Bonfiglioli, Head of Special Projects at Ferrari at the time, said that the car was developed in just 13 months. That means everything from the styling to the engine were taken from an idea to a production car in barely over a year. The engine wasn't quite a from-scratch design, though, since it was based on the unreleased 288 GTO Evoluzione's 650-horsepower engine, but it still received many updates to become the 487-horsepower engine we know today. Bonfiglioli highlighted the engine's weight savings due to using magnesium for the oil sump, cylinder head covers, intake manifold, and transmission bellhousing.
It was after driving one of those 288 GTO Evoluziones that Pininfarina designer Leonardo Fiorvanti learned about Enzo Ferrari's plan for the F40. He said that after telling Enzo his thoughts on the 288, Enzo told him he wanted to make a "true Ferrari." Fiorvanti also revealed that everyone, including Enzo, knew this would be the last car for the founder.
From what Ferrari test driver Bario Benuzzi said about the F40, it certainly didn't start out as a "true Ferrari." He said, "The handling of the first prototypes were poor." But in the short development time, the F40 became the car Enzo wanted, and Benuzzi credits plenty of downforce and the light, stiff chassis. It didn't make the car easy to drive, though. Benuzzi said, "With no power steering, power brakes or electronic devices, it demands the skill and commitment of the driver, but generously repays it with a unique driving experience."