The Tyrrell P34, commonly known as the "six-wheeler", was a Formula One (F1) race car designed by Derek Gardner, Tyrrell's chief designer. The car used four specially manufactured 10-inch diameter (254 mm) wheels and tyres at the front, with two ordinary-sized wheels at the back. Along with the Brabham BT46B "fancar" developed in 1978, the six-wheeled Tyrrell was one of the most radical entries ever to succeed in F1 competition and has been called the most recognisable design in the history of world motorsports.