Flat Bottom

The flat bottom regulation, introduced in 1983, required the underfloor of Formula 1 cars to be completely flat between the front and rear axles. This regulation was introduced to ban the ground effect tunnels that had been used since 1977, which were generating enormous downforce and making the cars extremely fast but also very dangerous — if the ground effect seal was broken (e.g., by a kerb), the car would suddenly lose all downforce. The flat bottom rule remained in force until 2022, when the new ground effect regulations were introduced. During the flat bottom era, teams found other ways to generate downforce — primarily through wings and complex bodywork.

The flat bottom regulation was introduced following the death of Gilles Villeneuve in 1982 and concerns about the safety of ground effect cars. The regulation was controversial — teams argued that ground effect was actually safer than wing-generated downforce because it was more consistent. The 2022 regulations reintroduced ground effect, but with strict rules about the shape of the floor to prevent the dangerous stalling that had occurred in the original ground effect era.