Ford Focus ST Mountune review

We’re looking forward to the new right-hand-drive Ford Mustang, which has been confirmed to go on sale in the UK. But the addition of this performance icon to Ford’s line-up means a new Focus RS is less likely to happen.

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However, fast Ford fans can get a cut-price Focus RS right now thanks to a Mountune power kit, which edges the 2.0-litre EcoBoost engine’s output closer to that of the old Focus RS’ five-cylinder.

It increases power from 247bhp to 271bhp (and torque from 360Nm to 400Nm) thanks to a new, larger intercooler that sits in front of the radiator, as well as a cast alloy air inlet duct that’s fitted on top of the car’s engine. There’s also an uprated, freer-flowing K&N air filter and the ECU has been remapped to make the best of the changes.

It costs an extra £1,275 if you choose a black finish for the intercooler and air duct, or £1,225 for silver. And while the only exterior change to the ST is a small Mountune badge on the bootlid, you immediately notice the extra low-down response.

Where the standard ST takes a little encouragement to get up and go, the Mountune kit has sharpened the car up noticeably. Although maximum torque is up by 40Nm, there’s actually around 90Nm extra on tap at lower revs, helping you build speed quickly.

In the wet, the Mountune has no trouble whatsoever getting the traction control to kick in – even at slow speed pulling away from a tight junction. So you need to be gentle with the throttle until you’ve built up some momentum. On dry roads, all that power through the front tyres means torque steer is unavoidable, and the ST’s weighty steering wheel wriggles around in your hands. It’s only a problem when you’re accelerating hard, but it’s quite significant, as the extra size of the Focus estate means torque steer causes the car to snake around quite dramatically as its front wheels hunt around for the line of least resistance.

Once you’re up to speed, the ST is as composed as ever, with an effortless directness to its steering. The suspension set-up is impressive, too: keeping the body flat, stable and in check over lumps and bumps, while still giving a comfortable ride.

Although throttle response has changed, the clutch is still heavy and the brakes are very strong. Apart from the extra power, the only change to the ST involves engine noise. The standard car has a pretty decent exhaust note, helped by a sound symposer that amplifies noise. But that’s now overscored by a vocal rushing of air through the filter and duct, plus a whoosh as the wastegate opens when you lift the throttle.

Mountune’s upgrade doesn’t affect the Focus ST’s three-year, 60,000-mile warranty, and can be fitted in 90 minutes by any Mountune-approved Ford dealer. And if you get your insurance through Mountune’s partner, Greenlight, it won’t affect your policy, either.