Can 360bhp Make The Ford Mustang Ecoboost More Appealing?

It’s hard to argue with the logic of the 2.3-litre inline-four turbo-powered Ford Mustang. It’s not that much slower than the 5.0-litre V8 GT, and is around 80kg lighter, which is mostly trimmed from the front. This means it’s noticeably keener to turn in and is the better car to drive fast. It’s also more economical - even though the gap in efficiency between the two isn’t quite as big as Ford might have you believe.

The Ecoboost, then, is the car I should want, and yet I’d have the GT every day of the week, because if I’m to have a slice of the ‘Murican dream in Europe, it’s damn well going to make all the right rumbly noises, thank you very much.

But what if the Ecoboost had say…360bhp? That’d give it a power-to-weight ratio approaching that of the GT, but in a lighter, more agile body. Thankfully, London-based luxury car dealer Clive Sutton has whipped up an Ecoboost with exactly that output, while adding much in the way of visual baddassery to what it calls the ‘CS350’ in the form of carbonfibre.

We have a new front splitter, rear diffuser, side skirts and boot trim all made from the stuff. It also sits lower on KW adjustable coilovers, and gets a set of wheel spacers to give the CS350 one hell of an aggressive stance. On closer inspection those rear vents are - I’m afraid - faker than Jason Statham’s American accent, but they work quite nicely with the whole package, don’t they?

Prodding the Mustang’s starter button (no horse heart rate pulsing here, we’re in a pre-facelift car) reveals a bassier din compared to what I’m used to from the 2.3. It’s thanks to Clive Sutton’s quad exhaust, which has switchable butterfly valves that are operated via a little keychain remote.

Is it an improvement on the noise front? Well, it certainly sounds meatier, and it’s quiet enough for long journeys when the valves are shut, but I’m not sure it’s an especially nice noise. This isn’t a mark against the system necessarily - I’m not sure there’s much you can do to make the Ecoboost engine sound any good. Even for a four-pot, it’s never been great.

There’s no dilemma with the straight-line performance though - the 2.3’s already punchy mid-range has been given a conspicuous uplift here. Once you’re past the initial turbo lag and so long as you’re over the 3000rpm mark, the CS350 can quickly and effortlessly build speed.

There’s a pleasing amount of poke on offer here, and while the delivery still isn’t all that hugely dramatic, I have no trouble believing that this would give a stock V8 GT a run for its money. It’s just a shame the test car has Ford’s sluggish six-speed automatic transmission fitted - a six-speed manual would have been a better ‘box to showcase the CS350’s talents.

The newfound power (torque has also increased significantly from 320lb ft to 376lb ft) is all thanks to a new cold air intake, intercooler and ECU tune. 0-60mph now takes just 4.8 seconds, down from 5.3. Much more like it.

What we’re less convinced about is the handling. The standard Ecoboost is noticeably more agile than the GT, but it’s still not a proper sports car. A set of coilovers doesn’t really change that, while adding the annoyance of a choppy low-speed ride. The stiffer setup does mean there’s a little more life in the steering than before, but the car can feel nervous on UK-spec (read: badly surfaced) country roads owing to the unforgiving damping.

It’s one of Clive Sutton’s options that’s best left un-ticked - just accept that this is a cruiser rather than a back-road stormer. Or, wait until the 2018 Mustangs are here with their much improved suspension setups, then give CS a call. The firm is already formulating a plan for the facelifted cars, and we’re looking forward to seeing the results.

But even if you leave the suspension off, speccing your Mustang like the pony you see here is not a cheap business. The power pack is a relatively reasonable £3600, but the price skyrockets if you fancy the carbon trinkets. The priciest is the £1700 carbonfibre rear valance for the quad exhaust system, which, by the way, is £2340. The total price of everything fitted here? £16,491. That’s the aftermarket for you - it becomes expensive quickly, if you get carried away by shiny things.

To answer my original question, yes: more power does increase the appeal of the Mustang Ecoboost. But for me, I’d still take my ‘Stang with a nice, noisy V8 - the four-pot version just doesn’t have the same sense of occasion even with more horsepower. It costs more to run, but if you’re getting a car like this, surely you have to do it ‘properly’?

Also, it just so happens that Clive Sutton offers a similarly priced power pack for the V8, which includes a louder exhaust. Or if you’re happy to throw a lot more money at your GT, there’s a Whipple supercharger conversion that punches the power beyond 800bhp…