The Cooper T45 was a Formula One racing car built in 1958 by the Cooper Car Company. It was built in a Formula-2 and a Formula-1 version.
The Cooper T45 was the successor of the Cooper T43. The chassis was almost unchanged, the front and rear suspension, however, were completely revised.
The engine was lowered, first drum brakes were used, but these were replaced in 1959 by disc brakes.
For the Formula 1 version it had a Climax a 2.2-litre engine, which developed 149 hp. Since this engine was exclusively available for the factory team, Rob Walker had the 2-litre engine that had less power.