Having offered engine tune-ups on the last Fiesta ST and the current Focus ST, Mountune Performance now has a powertrain upgrade for 1.6-litre Fiesta Zetec S and 1.6-litre Titanium petrol models.
The upgrade consists of a new induction system, a new exhaust, and some new software settings for the ECU of the Blue Oval’s Ti-VCT Sigma engine. After those changes that engine develops 138bhp at 6750rpm and 125lb ft of torque at 4250rpm (up from 118bhp at 6000rpm and 112lb ft at 4050rpm). And the extra poke means this Fiesta can dash to 60mph in just 7.9sec, down from around 10sec on a standard Zetec S.
A standard Fiesta Zetec S can be extremely entertaining to throw around, truth be told. It’s a car with excellent steering, fantastic ergonomics, a snappy gearchange and a lively, responsive and incredibly deft chassis capable of rewarding and cosseting the driver in equal measure.
What Mountune adds is a dose of extra fizz in the farther reaches of the Fiesta’s rev range. Below 4000rpm, the Mountune Fiesta performs almost exactly as a normal 1.6 does. There’s a louder, deeper and more characterful hum from the exhaust, but that’s all.
Keep your right foot pinned to the carpet beyond 4000rpm though and something altogether more remarkable happens. The rev needle’s clockwise progress towards 7000rpm quickens considerably.
There’s an audible change in the blare coming from those chromed tailpipes, and a more industrious chatter from the engine’s intake and exhaust valves, as the engine’s camshafts change gear. And there’s a new-found willingness to charge forwards from the car’s front wheels.
The first time you wring this little car right out to its 7000rpm redline, in fact, you’ll wonder if you didn’t pick up the keys to a VTEC Honda by mistake. You’ll be reminded that you didn’t, however, when you attack a choppy, broken B-road and find large reserves of composure in the Fiesta’s chassis.