What is it?
How much is too much? If you’re the engineering minds at fast Ford whisperers Mountune, then in fairness this question probably doesn’t really register, because when it comes to power (of the braked horse flavour), then you can never have enough. You want evidence? Look no further than the new M260 upgrade for the Fiesta ST.
Essentially the same set-up as the Essex tuner’s Puma ST, it comes hot on the heels of the M225 and M235 upgrades. As the name suggests, it boosts the 1.5-litre turbocharged triple’s peak power to 260PS, which is 256bhp in good old-fashioned money. That represents a 59bhp increase over the standard car and an extra 24bhp over the M235. The torque has been turned up, too, with a chunky 269lb ft now on tap at just over 3000rpm - although large wads of that figure are available from just 2000rpm. To put these numbers in perspective, the four-wheel-drive Toyota GR Yaris musters just 2bhp more and is 3lb ft shy of the Fiesta’s total twist action.
As with the lesser-powered versions, the M260’s extra urge has been liberated thanks to some careful software manipulation, which is downloaded to the car’s ECU using the firm’s Mtune Smartflash system. Simply plug the small Bluetooth dongle into the car’s OBD port, fire up the smartphone app and a few minutes later your Fiesta is a lot feistier.
Okay, that’s not strictly true, because to get the best out of the new mapping, you really need to change some of the hardware, too. For the sake of reliable performance in all conditions, the £675 microchip surgery should be bolstered by the addition of the brand’s bespoke £549 alloy intercooler, complete with the extra pipework (£165), as well as freer-breathing induction kit with performance panel filter (£239). Our car also had the £699 exhaust, which sits downstream of the catalyst and petrol particulate filter. Oh, and once all these bits have been bolted on, it’s important to remember that your fettled Ford should be fed only the highest-octane unleaded.
These modifications have been added to the firm’s M235 test car that we first drove last year, meaning that it also has a host of chassis and brake upgrades. Still not officially on sale, the suspension kit comprises 20mm-shorter springs that retain the original car’s stiffness, while the front brake overhaul adds 302mm discs and Brembo calipers for £1295. Inside, there’s the £99 short-shift arm for the gearbox, which reduces lever travel by around 25%.
Finally, to make sure nobody misses that you’re driving a saucier ST, there are some Mountune body stripes and rear spoiler extensions, plus a set of mud flaps that wouldn’t look out of place on the start line of the Grizedale or Sweet Lamb special stage.