Honda Racing started development of what would become the BGP 001 early in the 2008 season. When Honda announced their withdrawal at the end of that year, team principal Ross Brawn purchased the outfit and renamed it Brawn GP. Development continued under new ownership, and the car was redesigned to accept a Mercedes-Benz FO 108W V8 customer engine in place of the original Honda unit — a swap that required removing six inches from the rear of the car, severely affecting the centre of gravity. Only three chassis were ever built, compared to the eight or more commissioned by better-funded rivals.
The BGP 001 followed conventional 2009 practice in its carbon-fibre and honeycomb composite monocoque construction, with front and rear wishbone and pushrod suspension. Its defining feature was an innovative double-deck rear diffuser. The diffuser incorporated a hole in the central channel that increased airflow velocity into a higher venturi section, generating additional downforce. Teams including Ferrari, Renault and Red Bull lodged protests arguing the design violated the regulations; the FIA International Court of Appeal rejected the challenge on 14 April 2009 and cleared the car to race. The Mercedes V8 was rev-limited to 18,000 rpm per the 2009 regulations. A seven-speed semi-automatic gearbox was developed in-house, as Brawn opted against taking Mercedes's McLaren-designed transmission. The team also chose not to fit KERS, judging its weight penalty too high.
The BGP 001 made its competitive debut at the 2009 Australian Grand Prix, where Button took pole position and won the race, with Barrichello finishing second — a 1–2 on debut not achieved since 1954. Button took six wins in the first eight rounds: Australia, Malaysia, Bahrain, Spain, Monaco and Turkey. A mid-season performance deficit allowed Red Bull to close the gap, but Button's early points advantage proved decisive and he secured his first Drivers' Championship at the Brazilian Grand Prix. Barrichello won in Valencia and at Monza and claimed six podiums overall before finishing third in the standings behind Button and Red Bull's Sebastian Vettel. The car achieved podium finishes in every one of the first eight races.
A notable characteristic was that the BGP 001 performed better in warmer conditions; at the British and German Grands Prix, cooler temperatures prevented the car from bringing its tyres up to operating temperature. The car also suffered from a mid-season development freeze as rivals brought upgrades: McLaren and Red Bull surpassed it in outright pace during the second half of the year.
The car suffered one mechanical retirement, at Turkey when Barrichello lost seventh gear, and one crash retirement, when Button was collected in a collision at Belgium. At the Hungarian Grand Prix, a suspension spring parted from Barrichello's car during qualifying and struck the helmet of Ferrari's Felipe Massa, leaving him briefly unconscious and causing a serious head injury.
The car's win at Monaco was the first occasion in Formula One history where the same engine specification won three consecutive Grands Prix.
The BGP 001 used a Mercedes-Benz FO 108W naturally aspirated V8 engine, limited to 18,000 rpm as required by the 2009 regulations. A seven-speed semi-automatic sequential gearbox, developed in-house, was operated via paddle shifters. The car ran on Bridgestone tyres, the sole tyre supplier for the 2009 season, which also saw the reintroduction of slick tyres after an eleven-year absence.
When first shown, the car carried only Bridgestone and Brawn GP branding. Sponsors accumulated during the season, beginning with Henri Lloyd, followed by Virgin Group as a significant backer, and MIG Bank which eventually dominated the front of the car. Canon came aboard for Singapore, and Brazilian brewer Petrópolis displayed the Itaipava brand at the final round in Brazil. The rear wing carried Terminator Salvation film imagery at the Spanish Grand Prix.
The BGP 001 is widely regarded as one of the most unlikely championship-winning cars in Formula One history, emerging from a team with no sponsorship, a recycled chassis, and only three chassis built. Its double-diffuser design influenced rival teams, who scrambled to develop their own versions mid-season. All three chassis were later used by the successor Mercedes GP team as demonstration cars. The car appeared in the Codemasters F1 video-game series from F1 2009 onward, and was included as a classic car in F1 2018, F1 2019 and F1 2020.