Subaru Impreza WRX STI Cosworth CS400 GR
The ultimate UK-exclusive Impreza, forged by Cosworth to humble supercars.
- Power
- 400 bhp
- 0–60 mph
- 3.7 s
- Top speed
- 155 mph
- Est. value
- $55k–$75k
About the Subaru Impreza WRX STI Cosworth CS400 GR
The CS400 is a UK-only limited edition that marked the first road-car collaboration between Subaru and Cosworth since the legendary Ford Escort RS Cosworth. Based on the GR-generation hatchback, it features a heavily reworked EJ257 engine with forged pistons, high-strength rods, and a larger turbocharger to produce a staggering 400 PS. The chassis was significantly upgraded with Eibach springs, Bilstein dampers, and massive six-piston AP Racing brakes to handle the increased power. It remains one of the most accelerative and rarest production Subarus ever built, distinguished by its aggressive mesh grille and anthracite wheels.
Subaru Impreza WRX STI Cosworth CS400 GR specs
The Subaru Impreza WRX STI Cosworth CS400 GR produces 400 bhp (298 kW) and 542 Nm (400 lb-ft) of torque. It reaches 60 mph in 3.7 seconds and has a top speed of 155 mph (250 km/h).
| Make | Subaru |
|---|---|
| Model | Impreza WRX STI Cosworth CS400 |
| Generation | GR |
| Trim | 2.5 |
| Years | 2010–2011 |
| Type | Sports car |
| Body style | Hatchback |
| Country | Japan |
| Production | About 75 built |
| Engine | 2.5-litre turbocharged flat-four |
|---|---|
| Displacement | 2,457 cc (2.5 litres) |
| Induction | Turbocharged |
| Power | 400 bhp (298 kW) at 5,750 rpm |
| Torque | 542 Nm (400 lb-ft) |
| Redline | 6,700 rpm |
| 0–60 mph | 3.7 s |
| Top speed | 155 mph (250 km/h) |
| Transmission | 6-speed manual |
| Drivetrain | All-wheel drive |
| Weight | 1,505 kg (3,318 lb) |
| Power-to-weight | 266 bhp per tonne |
Typical figures for the standard car; options, markets and model years vary. Where our specs come from
How much is a Subaru Impreza WRX STI Cosworth CS400 GR worth?
A typical Subaru Impreza WRX STI Cosworth CS400 GR is estimated to be worth $55,000 – $75,000 (about £41,000 – £56,000).
Values are directional estimates for a typical example, not appraisals. Condition, mileage, history and specification all change what a real car is worth. Pound figures use the exchange rate of 3 November 2026. How values are estimated
Subaru Impreza WRX STI Cosworth CS400 GR rarity in CarSpot
The Subaru Impreza WRX STI Cosworth CS400 GR is a Unicorn card in CarSpot, with a rarity score of 100 out of 100. The rarest tier: hypercars, one-offs and cars built in tiny numbers, typically fewer than about 500. A Unicorn card is worth 320 XP.
Each model's tier starts from a 0–100 score based on its value plus its power or production numbers. Once enough players have spotted a model, how often it is spotted can move it up or down one tier. How CarSpot rarity works
Rarity is a collectible game mechanic, not an assessment of real-world scarcity or value.
Subaru Impreza WRX STI Cosworth CS400 GR fun facts
- Despite its massive power hike, the CS400 retained Subaru's full factory warranty at launch.
- The car's 0-62 mph time of 3.7 seconds was identical to the Ferrari 599 GTB Fiorano of the same era.
- Only 75 units were produced, all in right-hand drive for the British market, making it rarer than the iconic 22B.