When, in 1966, the maximum displacement of F1 engines increased to 3 liters, the double of what was allowed until then since 1961, Lotus was forced to find an alternative to the usual Coventry-Climax.

Colin Chapman, always very dynamic and creative, relied on Walter Hayes, Ford's public relations in Europe, to convince the American manufacturer to bear the costs (about £ 100,000) of designing and building a new engine by the Cosworth company of Mike Costin and Keith Duckworth.

The new Ford Cosworth DFV (Double-Four-Valves), a V8 at 900, delivered about 400 CV at 9,000 rpm and, even though it was less powerful than Ferrari's 12 cylinders, it was lighter and frugal, proving to be extremely competitive and the biggest asset of the new Lotus 49.

As was the tradition at Lotus, the 49 was a simple car and as light as possible. Its greatest originality was the use of the engine/gearbox assembly as a structural element. The monocoque chassis, in aluminum, allowed this technological advance.

The chassis of the racing cars were, until that time, designed with an extension behind the cockpit, which served as support for the engine/gearbox assembly and the rear suspension.

In 49, Chapman and his designer, Maurice Philipp, designed the chassis to finish at the bulkhead behind the driver's seat, with the engine fixed to its rear face. This solution have been followed, until today, in all categories of formula and sports cars.

For the suspensions, upper balancers and lower triangles were used at the front, with the spring and shock absorbers mounted inside the bodywork, and at the rear, upper rods and inverted lower triangles supported on the gearbox, longitudinal arms supported on the rear bulkhead of the chassis and spring and shock absorbers mounted next to the gearbox.

The new Lotus won in the debut race in Zandvoort, at the 1967 Dutch Grand Prix, having won a total of 12 GP victories until 1970's Monaco, and ended his career the following year.

With this model Lotus won two Drivers' and two Constructors' Championships, in 1968, with Graham Hill and in 70, with the posthumous title of Jochen Rindt.

The original gearbox was from ZF and was the source of multiple reliability youth problems of the 49, having been replaced by one from Hewland, also with 5 speeds, the following year.

The 49B was presented in 1968, at the Spanish GP, and the following, in Monaco, Lotus debuted a rear spoiler over the gearbox and the new Gold Leaf decoration, replacing the original, in British green with the yellow central stripe.

That year, the front and rear wings, copied from Chaparral's Sport models, began to be used in Formula 1 cars.

Ferrari was the first in Spa, followed by all the other teams. In a short time, the wings were assembled in undersized structures, supported by the suspension elements, having occurred the inevitable accidents that led CSI, the FIA's technical arm, to limit its use.

In 1969, Lotus planned to introduce the 63 model, which proved to be a failure and had to develop the 49C, which did not hinder the success of Jackie Stewart and Matra-Ford of Ken Tyrrell's team.

Lotus returned to the titles in the tragic year of 1970, in which, despite the death of Jochen Rindt, he secured both Championships, having used the 49C alongside the development of the new and also innovative 72 model.

The Lotus 49 was driven by 4 World Champions, Jim Clark, Graham Hill, Jochen Rindt and Emerson Fittipaldi, and by other great drivers, such as Jo Bonnier and Jo Siffert, the latter being the last driver to win a GP race by a private team, with Rob Walker's car, at the 1969 British GP.