Lotus 25
The Lotus 25 was the first monocoque F1 car, and the advantages of this method of construction allowed it to dominate the 1.5-litre era of F1, in the early to mid-1960s. The car gave Lotus its first World Championship, and a development of it even won the Indianapolis 500.
It was Lotus boss Colin Chapman's fanatical search for lower frontal area that caused him to stumble upon the idea of the monocoque hull. Looking for ways to dispense with the steel tubes of the chassis around the cockpit area to further slim the car down, he made the aluminium skin of the car double as the chassis itself. The previous method of forming the load bearing structure from steel tubes, which were then covered with non-structural panels, was rendered instantly obsolete.
But the monocoque design brought advantages far greater than merely providing a slimmer body. It was much stiffer and more resistant to twisting, allowing the suspension to do its job far more effectively. It was also much lighter.
Chapman had kept the car a secret — even entering early-season non-championship races with the Lotus 24, an update of his previous season's 21 with conventional space-frame chassis — but from the 25's debut in the 1962 Dutch Grand Prix, it was evident that this was where the future lay.
In Jim Clark's hands, the Lotus 25 went on to prove conclusively that it was the fastest car of the season, although it was thwarted from winning the championship in the final round by unreliability. This was corrected for 1963, when Clark took a record seven wins on his way to the title. A wider-wheeled version, dubbed the 33, also took the crown in 1965, the same year that a beefed-up Indycar derivative won the Indy 500 with Ford V8 power.
