The undercar pressure problems in the 78 were resolved with the 79, with further design work on the venturi tunnels under the car, which allowed the low pressure area to be evenly spaced along the whole of the underside. This was achieved by extending the rear bodywork to a point inside the rear wheels, allowing the underside to extend further back, instead of ending abruptly in front of the rear wheels as on the 78. As a result, the rear suspension was also redesigned to allow the air to exit the rear more cleanly than on its predecessor. This allowed a smaller rear wing to be designed, causing less drag. When the car first appeared, the upper bodywork was steeply raked and featured “Coke bottle” sidepods. After work in the wind tunnel, these features were found to be unnecessary, as the car generated so much downforce anyway. These features were, however, later incorporated into the Lotus 80. In all, five chassis were built during the design’s lifetime, with the prototype 79/1 being sold to Héctor Rebaque to race as a privateer entrant.
The car was powered by the Ford Cosworth DFV and constructed of sheet aluminium honeycomb, specially strengthened for the pressures exerted on the car by the ground effect. The fuel tank was one single cell behind the driver, as opposed to separate fuel tanks as on the 78. This had the advantage of increasing fire protection and moving the centre of gravity to the middle of the car, helping cornering and braking. The 79 was also the first F1 car to be designed using computer design aids. In fact, it was the first F1 car to use computers to analyse it in the pits on race weekends.
The car was secretly tested in late 1977 by Ronnie Peterson and proved extremely fast, but the chassis suffered early fatigue due to the severe suction and g-forces generated by the ground effect. The 79 produced about 30% more downforce than the 78, something not foreseen by Ogilvie and Rudd, who went back to the drawing board. The chassis was strengthened in specific points, mostly around the monocoque and load bearing points on the chassis tub, and the car was found to be even faster than before.
The need for smooth airflow dictated the car must have clean lines. Nicknamed “Black Beauty” by the press and F1 fans alike, for its graceful design and sleek profile and its black and gold livery through sponsorship by John Player Special cigarettes, the Lotus 79 was instantly competitive on its debut, the 1978 Belgian Grand Prix at Zolder. It took pole at the hands of Mario Andretti by more than a second, and won the race comfortably. Andretti said after driving the 79 for the first time that the Lotus 78 was like driving a London bus. Peterson once quipped, after scoring an impressive pole position, that the car was so brilliantly set up, all he had to do was steer.
The 79 was not without its problems, however. Wright and Ogilvie noted that the car was very marginal in some aspects of its design. Andretti had reservations over the car’s brakes, which faded noticeably over a race distance, especially in hot conditions; the exhaust had a tendency to overheat, and the monocoque tub was not as stiff as the team would have liked, which meant a new casting had to be fabricated several times during the two seasons the car was used.
The 79 proved to be almost unbeatable during the 1978 Formula One season and provided an unprecedented level of domination. The car took six more victories during the season giving the drivers’ championship to Andretti, and the constructors’ championship to Lotus. Its only serious rivals during the season were the Ferrari 312T3, and the advantage its Michelin tyres gave in hot weather conditions, and the Brabham BT46B “fan car”. The fan car only raced once, winning the 1978 Swedish Grand Prix, before Brabham voluntarily withdrew the car. Meanwhile, the Ferraris only won when the Lotus failed to finish. So superior was the Lotus, that most races became a scrap for minor placings, as Andretti and Peterson regularly finished first and second, more often than not by a considerable margin ahead of the rest of the field. On the rare occasion the 79 did not win or fail, one or other driver was usually on the podium. Andretti was comfortably world champion in 1978, and Peterson finished the season as the runner-up, although posthumously, as he died after a startline crash at Monza, the race where Andretti wrapped up the championship. Peterson was not in the 79 for that race; he drove the previous year’s 78 due to a severe crash in practice and him being unable to fit into Andretti’s spare car. Jean-Pierre Jarier took over the second Lotus for the rest of the season and was leading the race in both America and Canada — he also grabbed pole position in Canada — until the 79 suffered mechanical failures in both. It proved, however, that even with a lesser driver, the 79 was still competitive.
In 1979, the 79 was to be replaced by the Lotus 80, intended to be the next step in the evolution of ground effects. Martini Racing replaced JPS as sponsor in that year, so the car appeared in British racing green. The 80 proved to be a total failure and Lotus was forced to go back to the 79, driven by Andretti and Carlos Reutemann. Several podium places were scored and the 79 was in contention for victory in the early stage of the season, but the next generation of ground effects cars led first by the Ligier JS11, then Ferrari 312T4 and then Williams FW07 — a car heavily based on the 79 — outclassed the Lotus. Although the car was updated with revised bodywork and a new rear wing, Lotus slipped to fourth in the constructors’ championship and the car was retired at the end of the 1979 season, without winning any further races. The 79 did however provide Nigel Mansell with his first Formula One test in December 1979 at Paul Ricard.
In its lifetime, the 79 took 7 wins, 10 pole positions, 121 points and won the last drivers’ and constructors’ world championships for Lotus. The 79 is credited with pushing Formula One into the aerodynamics era, and its influence is still keenly felt on today’s modern F1 cars. After Rubens Barrichello drove the 79 at the Goodwood Festival of Speed in 2000, he came away raving about its phenomenal grip and traction, and stated it felt like a modern Grand Prix car.