CJ Hubbard
10/11/2010 11:34 | By CJ Hubbard, contributor, MSN Cars

Subaru Cosworth Impreza STI CS400 review (2010 onwards)

Subaru Cosworth Impreza STI CS400 (© Motoring Research)

What - Subaru Cosworth Impreza STI CS400
Where - Hertfordshire - Buckinghamshire, UK
Date - October 2010
Price - £49,995
Available - Until all 75 are sold
Key rivals -Mitsubishi Evo FQ400, Honda Civic Type R MUGEN, Porsche Caymen S, the space shuttle

Summary - Subaru lets Cosworth at the Impreza to spectacular effect. This car is so fast it will actually set your trousers on fire.

We like - astonishing traction and performance, exclusive, a real Cosworth road car
We don't like - not the most sophisticated device, interior always a let-down, lacks depth

Gallery: Subaru Cosworth Impreza STI CS400

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First impressions

Subaru Cosworth Impreza STI CS400 rear (© Motoring Research)

The names 'Subaru Impreza' and 'Cosworth' are, individually, heroes of everyman performance. In many respects the four-wheel drive turbocharged capability of the Impreza WRX and STI carried on where Cosworth-fettled turbocharged Fords left off.

So, it doesn't take a genius to work out that when Subaru announced it had asked Cosworth to develop perhaps the ultimate Impreza special edition, right here in the UK, the news was greeted with a fair degree of anticipation.

Welcome, then, the new dark lord of high performance hot hatches - the Subaru Cosworth Impreza STI CS400. Finished here in Dark Grey (as opposed to the alternative choices of Spark Silver or San Remo Red) it is somehow subtle but also absolutely menacing.

Subaru Cosworth Impreza STI CS400 zooming along road (© Motoring Research)

This Impreza is the first 'genuinely-Cosworth developed' road car since 1996; the Northampton-based company has spent the intervening years doing insignificant things like, oh, building Formula 1 engines.

This goes some way to explaining the £49,995 asking price. That and the fact it really is UK-only, and there will only ever be 75 of them. But for this sort of money the Cosworth Impreza really had better be good...

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Subaru Cosworth Impreza STI CS400 side action shot (© Motoring Research)

To say this car has pedigree is one of 2010's great moments of understatement - swiftly followed by a colleague's remark that the car itself is 'a bit quick'. Cosworth has taken the 2.5-litre boxer turbo engine always at home under an Impreza STI's bonnet, and increased its output by 33%.

That's a third, just to reiterate, in case you weren't paying attention. In plain figures it's gone from a not inconsiderable 300hp to a whopping great 400hp - a 100hp gain, accompanied by a similar swelling in the department of neck-snapping torque.

The new 400lb ft max, shifted higher up the rev range, gives this car overtaking performance we don't think you can truly comprehend unless you've actually experienced it - and even then you may not believe it until you've done it again. And again. And again.

It's been some considerable time since we've driven anything that caused us to swear in shock quite so much. As well as significantly altering the turbo system, Cosworth has rebuilt the engine with stronger internals, remapped the ECU and fitted a free-flowing exhaust; the result is riotously old skool.

Subaru Cosworth Impreza STI CS400 around the corner (© Motoring Research)

It isn't actually an all or nothing hammer - while there is most definitely BANG, we wouldn't describe the lower end of the rev counter as lethargic. It's more that when the action really starts, the urgency available below 4,000rpm pales into utter insignificance.

With 4k on the dial you can almost see the imaginary flames from the afterburner Subaru apparently forgot to list on the spec sheet - the bassy, pulsing, duggadugga beat so Impreza-typical suddenly overlaid by a scorching whoosh, as the Cosworth attempts to inhale half the atmosphere and spit it out the back end as forward momentum.

This thing can seriously move. But as the really big wallop is all over again by about 5,500rpm it does so in a series of huge, hungry lunges, rather than one unrelenting push. Probably, this is for the best - otherwise you'd be contacting air traffic control for permission to take off - but together with the slightly sticky gearshift the Cosworth lacks some fluidity.

No denying the impact, though - 0-62mph takes just 3.7 seconds. Which is not only nearly two seconds faster than a Ford Focus RS 500, and 0.1 seconds faster than a Mitsubishi Evo FQ400; it's also as quick as a Lamborghini Gallardo LP560-4.

Ride and handling

Subaru Cosworth Impreza STI CS400 rear (© Motoring Research)

So this is one hot hatch that really is a supercar killer. Naturally, Cosworth has also worked its magic on the suspension, fitting bespoke Bilstein damper inserts together with unique Eibach springs, plus new 18-inch alloy wheels that give the car a wider track.

This leaves the front end 15mm lower while claiming to deliver better ride quality with greater control over pitch and roll in the corners. The ride is still firm, but it's far from unbearable, and the damping does a brilliant job of keeping the Subaru pointed as directed, no matter how lumpy the tarmac gets.

But if the Evo FQ400 is categorically a weapon - all razor sharp response and sizzling precision - the Cosworth Impreza is more blunt force trauma. Delicacy is not on the agenda. Just step on the loud pedal and hold tight.

The first thing that strikes you is the almost total lack of steering feel. This gets better as the car goes faster, like legal speeds aren't even worth the sweat; grip in regular driving should be taken on trust, absolutely - the four-wheel drive isn't even trying.

And it's in this respect that the Cosworth Impreza becomes almost astonishing. Body roll may be diminished, but it's certainly not gone altogether - so with the information-free front end and the way the car is leaning you find yourself bracing for understeer as soon as you touch the accelerator mid-corner.

Subaru Cosworth Impreza STI CS400 front (© Motoring Research)

It never happens. Instead Subaru's 'Symmetrical All-Wheel Drive' seamlessly shuffles the under bonnet explosion to maximise whatever purchase the car can get on the road surface - and it simply grips and goes. Wildly fast in a straight line becomes devastating cross-country.

The usual SI-Drive and centre differential adjustment gizmos remain, enabling alterations to the throttle response and/or torque distribution between the front and rear wheels - so you can even exit corners with an oversteer flourish. But we found the 'Sport' setting worked perfectly well by itself.

AP Racing front brakes also come as part of the package, delivering stupendous, fade-free stopping power. Drivetrain weak point seems likely to be the six-speed gearbox; even with upgraded 'carbon' syncromesh on the top three gears, our 7,000-mile-old test car was occasionally crunching changes into fourth.


Subaru Cosworth Impreza STI CS400 interior (© Motoring Research)

Still, in all fairness it's probably had a significantly hard life (put it this way - there were two press cars originally; there aren't any more. We won't tell you what happened to the other one, but it wasn't us). All the more reason to be impressed by the essentially unmarked interior.

As befits a bespoke model there are Cosworth branded front seats, finished in not especially convincing leather. There's also some piano black trim and a Cosworth sticker on the dashboard that, due to the contours it's attached to, doesn't look straight. STI business as usual, otherwise.

Economy and safety

Subaru Cosworth Impreza STI CS400 in car park (© Motoring Research)

No-one who buys this car is going to care what sort of fuel economy the Cosworth Impreza is supposed to return. Which is handy, given Subaru has written 'TBC' in the spec sheet. Expect single digit mpg on a hard run, but turbo efficiency means a reasonable return on the motorway is entirely possible.

Safety is as per usual with an Impreza, but with the added reassurance of the monster AP Racing brakes plus the immense engine's ability to out-run an angry, vindictive - think Norse mythology or something - god. Electronic limit at 155mph be damned. Etc.

The MSN Cars verdict

5 stars

As with the Honda Civic Type R MUGEN, another mega-money hot hatch, it's no exaggeration to say we're looking at a legend in the making here - the Subaru Cosworth Impreza STI CS400 is a truly remarkable machine.

We're not convinced it has talent in depth the way other machines in this price range do (Porsche Cayman S anyone?), but for the select clientele it's aimed at, the Cosworth Impreza is surely divine.

It isn't perfect - not by a long shot - but the gargantuan performance is just so useable it defies belief.

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Need to know 
Engines, petrol2.5 turbo Cosworth
Engines, dieseln/a
Power, hp400
Torque, lb ft400
0-62 mph, secs3.7
Top speed, mph155 (electronically limited)
Mpg combinedTBC
CO2, taxTBC
RatingsSubaru Cosworth Impreza STI CS400
Ride & handling****
Fuel economy*
MSN Cars verdict*****

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