For more than a decade now, Mountune's work on the Fiesta ST has yielded some of the finest fast Ford entertainment available. In 2008, it was thanks to some traditional NA tuning of the 2.0-litre ST - spikier cams being a notable feature - that the slightly wheezy Fiesta engine achieved proper firecracker status.
Understandably given the popularity of the previous Fiesta ST, further Mountune options became available and with a Ford warranty behind it, the Performance 215 kit was a real success. And with good reason: fitted to our long term Fiesta for less than the price of some of the metallic paint options, the MP215 made a great car even better with no impact on drivability.
Now the tuner has launched the same level of upgrade for the three-cylinder ST. As before, the changes are relatively modest (induction changes and new calibration) but elicit some worthwhile gains: 225hp is an additional 25hp over standard, while a new torque peak of 251lb ft is up 37 points. And broadly competitive with larger hot hatches from the class above, in fact - a 275hp Hyundai i30 N makes 260lb ft, the 308 GTI an identical 251lb ft.
Predictably, it's that barrel-chested torque figure that has the greatest impact on the road. That's certainly no bad thing, either, given the standard 1.5-litre Ecoboost is a three-pot which trades more on its lusty mid-range more than it does frenzied high revs. Like the previous Performance kit on the four-cylinder car, the M225 represents more of what was already good about the standard version, without compromise: more noise, more urgency, more performance, more fun. Why, after all, spoil such a good recipe? The subtlety and finesse of Mountune's work is perhaps its greatest strength. Ford, after all, does not need that much help.
On the road, the M225 is exactly how you'd hope a lightly tweaked Fiesta ST would be. There's an addictiveness to how hard it pulls every ratio, the torque providing in-gear possibilities that aren't quite there in the standard model. Moreover, at its peak, it is demonstrably quicker than normal, with all the juvenile entertainment that comes from something so small being hurled down a road so rapidly.
There's also a sneaking suspicion that the Mountune'd car might rev a little more freely than standard, although we'd need a back to back comparison to be sure. It could very well be the placebo effect, caught up in the torque and the raspier soundtrack of the Sport and Race modes which have also been tweaked. One thing the ST could never be accused of is torpidity, yet that energetic nature is front and centre here.
Essentially then, as it was before, the Mountune's Fiesta ST package is a no-brainer; at £795 plus fitting from a reputable brand, and with the world-first app installation, it's laughably easy to recommend.
It's probably clear from the pictures, however, that this ST isn't just sporting some extra power and torque. As Mountune's demonstrator, M999 FST also comes with a big brake kit - four-piston front calipers, 330mm discs, upgraded pads and braided lines - prototype lowering springs, a quickshift kit and 18-inch Turbomac wheels from fifteen52 (Mountune now of course working with the US firm on VW tuning - more of which to follow soon).
The chassis modifications felt a bit OTT for a wet and windy June day in the Essex countryside - or rather, forced to operate at commitment levels that made them feel unnecessarily overspecced. No doubt this sort of braking performance and security of body control would be ideal for a dedicated track project; here though they take away as much from a great road car in their occasional abruptness as they add in potency and ability. While the brakes in particular delivered immense power, the standard set up would be sufficient for the road, even with the M225 kit fitted. The quickshift does feel to have taken some slack out of the gearbox, too, it should be noted.
And that's the joy of modifying - you can add as much or as little as you want, depending on budget, ambition and preference. For those that won't use their car on track, there will be no need for brake and suspension changes, so they won't have them. All Fiesta ST buyers should get the basic Mountune upgrade, though - even those with bigger plans ahead, because the work is modular, so the air box used here will support more serious modifications in the future. And for those simply seeking more fun from an already brilliant little car, the M225 hits the nail on the head with all the precision we've come to expect from its maker.
By seeking to enhance rather than transform the ST package, it feels like an in-house development - and given Ford's towering reputation in the segment, there can be no higher praise. Get a Performance Pack car with this fitted and you won't find a more enjoyable new hot hatch for the money. And by the time boredom sets in - if it ever does - Mountune should have the second stage of upgrades ready to go...
SPECIFICATION - FORD FIESTA ST M225
Engine: 1,497cc, 3-cyl turbocharged
Transmission: 6-speed manual, front-wheel drive
Power: 225@NA rpm
Torque: 251@NA rpm
0-60mph: 5.95 sec
Top speed: 144mph (standard car)
Weight: 1,262kg (EU, with driver)
MPG: 47.1 (standard car)
CO2: 136g/km (standard car)
Price: £795 kit (without fitting), Fiesta ST from £18,995