This is the very first sports car with a six-cylinder in-line engine, although another three-litre 306 engine was also been built but never used in competition. Actually, all of the six-cylinder in-line engines were really extrapolations of the four-cylinders, sharing the same bore and stroke with a piston displacement of about one and a half times the size of the latter. Here the 37 of the 376 refers to the piston displacement (divided by 100), while the 6 refers to the number of cylinders.