| Car Name: | Lotus 81 |
| Category: | Formula One |
| Constructor: | Lotus |
| Wc Results Only: | Y |
| Designer: | Colin Chapman (Technical Director) Martin Ogilvie (Chief Designer) Peter Wright (Head of Aerodynamics) |
| Predecessor: | 80 |
| Team: | Team Essex Lotus |
| Drivers: |  Mario Andretti Elio de Angelis Nigel Mansell |
| Chassis: | Aluminium monocoque |
| Front Suspension: | Double wishbones, coil springs over dampers, anti-roll bar |
| Rear Suspension: | Double wishbones, coil springs over dampers, anti-roll bar |
| Length: | 4623NaN |
| Width: | 2134NaN |
| Height: | 965NaN |
| Wheelbase: | 2789NaN |
| Track: | Front: 1700NaN Rear: 1638NaN |
| Engine Name: | Ford Cosworth DFV, |
| Configuration: | 90° V8, |
| Capacity: | 29931NaN1, |
| Turbo/Na: | NA, |
| Engine Position: | mid-engine, longitudinally mounted |
| Gearbox Name: | Hewland FGA 400 |
| Gears: | 5-speed |
| Type: | manual |
| Weight: | 580NaN |
| Fuel: | Essex |
| Tyres: | Goodyear (1980) Michelin (1981) |
| Debut: | 1980 Argentine Grand Prix |
| Last Event: | 1981 Belgian Grand Prix |
| Races: | 18 |
| Wins: | 0 |
| Cons Champ: | 0 |
| Drivers Champ: | 0 |
| Poles: | 0 |
| Fastest Laps: | 0 |
| Podiums: | 2 |
The Lotus 81 was a Formula One racing car built by Colin Chapman's Lotus team for the 1980 Formula One season. Unlike many of forebears the 81 was not a terribly innovative or competitive car, coming as it did at a time when Chapman's interest in his racing activities was waning.
Instead it was a very standard ground effect design with sliding skirts and the ubiquitous Cosworth DFV 3.0 litre V8 powerplant. The car was said to generate a great deal of downforce but have excessive pitch sensitivity problems, ultimately leading Chapman to develop the innovative twin-chassis Lotus 88.
Mario Andretti and Elio de Angelis used the 81 in all 14 rounds of the 1980 Formula One world championship, and the car also gave Nigel Mansell his Formula One debut, with the British driver lining up in a total of three races that season. The best result for the car was Elio de Angelis's 2nd place in Brazil.
Chapman had intended to use the Lotus 88 for the season, but a massive furore over the legality of the new car meant that the 81 was kept on as a stop gap for the first four races Lotus competed in, as they boycotted the 1981 San Marino Grand Prix, with Mansell taking 3rd place in the Belgian Grand Prix and de Angelis claiming three points finishes. The car was replaced by the Lotus 87.
(key)
| Year | Entrant | Chassis | Engine | Tyres | Drivers | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Points | WCC |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Team Essex Lotus | 81 | Ford Cosworth DFV | ARG | BRA | RSA | USW | BEL | MON | FRA | GBR | GER | AUT | NED | ITA | CAN | USA | 14 | 5th | ||||
| Mario Andretti | Ret | Ret | 12 | Ret | Ret | 7 | Ret | Ret | 7 | Ret | 8 | Ret | Ret | 6 | ||||||||
| Elio de Angelis | Ret | 2 | Ret | Ret | 10 | 9 | Ret | Ret | 16 | 6 | Ret | 4 | 10 | 4 | ||||||||
| 81B | Nigel Mansell | Ret | Ret | DNQ | ||||||||||||||||||
| Team Essex Lotus | 81B | Ford Cosworth DFV | USW | BRA | ARG | SMR | BEL | MON | ESP | FRA | GBR | GER | AUT | NED | ITA | CAN | CPL | 22* | 7th | |||
| Nigel Mansell | Ret | 11 | Ret | 3 | ||||||||||||||||||
| Elio de Angelis | Ret | 5 | 6 | 5 |