ZeroNine Ford Focus ST review – Ferrari 599 pulling power in a hatchback

Production of the Ford Focus has just ended for good, and that means the Focus ST has joined the likes of the Renault Mégane RS, Hyundai i30 N and Ford's own Fiesta ST in the graveyard of petrol hot hatches. Sad, but not surprising. It's getting harder and harder to sell the hot hatches we love, stringent emissions regs and the ZEV mandate working against them, ushering them out to make way for electric alternatives. Even the unstoppable Honda Civic Type R won’t survive beyond next year. Get a hot hatch while you can, we'd say – and if the Focus ST is your chosen flavour, you might want to pay Leicestershire firm ZeroNine a visit. 

You probably haven’t heard the name before – the company only launched in spring – but those behind ZeroNine have been in the aftermarket tuning game for years, acting as an engineering resource for other companies to design and manufacture components. It’s now selling performance upgrades under its own ZeroNine banner, including for the last-of-the-line STs (upgrades for the Toyota GR Yaris have been developed too). More power, more noise, better drivability and handling improvements are the name of the game, without pushing the standard componentry to breaking point. 

We like, if not love, the Mk4 Focus ST. It’s hugely capable on track but doesn’t have the deftness of the smaller Fiesta on the road, nor the locked down precision and feedback of a Civic Type R. ZeroNine offers a series of dynamic upgrades to fix that, such as a lowering spring kit (£144), a CNC-machined transmission tunnel brace (£115) and a subframe ‘lockdown kit’ (£93), to keep the front and rear structures centralised under load. The power steering calibration has been tweaked in the Focus’s sportier drive modes too, while upgraded brakes with monobloc six-pot front calipers hide behind OZ Estrema wheels. 

The major upgrades are targeted at the engine, however. The ST’s 2.3-litre EcoBoost motor has always favoured low-end grunt rather than peak power, and that’s still the case here – even more so in fact. Power rises from 276bhp to 329bhp and torque takes a huge 128lb ft leap to 438, thanks to a carbon induction kit (£575) and crossover pipe (£300), a high-flow charge pipe (£275) and a software upgrade (£550). If you’re wondering how on earth two front tyres can take Ferrari 599 levels of twist, so were we…

As well as all of the above this ZeroNine development car has a freer-flowing stainless steel exhaust, and there’s a bassier burble as soon as you’re underway. That aside, left in Normal mode the ST is so far, so familiar, and it doesn’t feel like a highly-strung tuner car. The engine is docile and the ride is firm, sometimes brittle over poor surfaces, but not too jarring. There’s usable torque to work with and the controls are easy – perhaps too easy in the case of the gearshift, which isn’t especially short or tactile. An upgraded linkage would be nice. 

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To feel the full force of the upgrades you need to sharpen the throttle by switching to Sport, and keep it pinned beyond 2500rpm. Then the delivery becomes rabid and the ST pulls with tremendous force, launching up the road in a flurry of turbo whoosh and torque steer. The performance is mighty and, surprisingly, the front tyres can put almost all of it down, but you do need a firm hand to fight the wheel and keep the nose on line. In some ways the nature of the engine doesn’t suit a hot hatch – like the standard car there’s no need to wring out every gear to seek out the top end – but the extra power comes where you need it most on a technical road, in the mid-range. 

Sport mode also changes the steering map, and though it’s more positive than Normal, it's still some way off the natural tactility of a Civic Type R. It’s an odd combination of a darty, heavy on-centre feel and a lack of weight build up as you wind on lock, which doesn’t give you confidence to fully lean on the front tyres. But you really can lean on them, and the ST’s front end is as nailed down as usual – perhaps more so. It turns in with real tenacity, whether floating into high speed corners or holding the brakes into tighter ones, and there’s a satisfying sense of yaw that builds as you get to the heart of a bend. The brakes need a firm push initially but there’s good bite and feel deep into the pedal, too. 

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Switch to Race and ZeroNine’s software changes make the ST even more lively, but in many ways the dial is turned too far. The throttle becomes jumpy and tricky to modulate, and the steering takes on more weight which damps out most of the feel. The machine-gun shots on the overrun are a bit much, too. Sport is a much better balance for the road.

Though the ZeroNine mods – chiefly those to the engine – do bring elements of the experience to life, the ST’s usual niggles remain. The dynamic improvements are marginal, and there’s still a lack of finely honed detail from the controls, and a fiery top end to chase. But it’s still a thoroughly enjoyable hot hatch, and if you own one and want to go quicker, the ZeroNine upgrades emphatically deliver while staying on the right side of rowdy – just.