Ford Fiesta ST Mountune m235 review: 232bhp Fiesta tested

A new Fiesta ST Mountune? Hell. Yes.

Hold your horses. See, back in the day Mountuning your Fiesta ST was a bit of a no-brainer. For just £599 you got a new airbox, air filter and ECU tweak giving more power – 212bhp, up from 178bhp. Your local Ford dealer could fit it in next to no time, and crucially it didn’t invalidate your warranty.

Nowadays things are different. Ford doesn’t warranty Mountune’s kits anymore, so anyone looking to modify their new ST from day dot is taking bit of a risk – in the event something breaks, Ford isn’t obligated to pick up the tab. 

Oh. Is it worth getting anyway?

Not right away, no. Mountune’s kits come with a 12-month/12,000 mile warranty, but we say keep your Ford warranty, and for three years enjoy the car as the Blue Oval intended. It’s pretty bloody good straight out of the box, and you can feel safe in the knowledge that in the unlikely event a critical mechanical component dies a tragic and premature death, Ford has you covered. 

Then give Mountune a ring and ask for the m235 kit. It costs £795 and, much like the upgrade for the old Mk7 Fiesta ST, consists only of a new airbox, air filter and a few lines of code.

You can order it online and fit it yourself in minutes. Bit of tinkering under the bonnet, then plug the supplied dongle into the OBD2 port under the dashboard, Bluetooth it to your phone and configure using Mountune’s ‘Smartflash’ app. Boom. (Well, not literally 'boom'. Hopefully.)

What does it give me?

Chiefly, power. Mountune’s kit increases power and torque from 197bhp and 214lb ft to 232bhp and 258lb ft. 0-62mph is down to 5.9 seconds, but more importantly the tuner claims its Fiesta is over a second quicker from 31-62mph than the standard car.

You also get more noise and more aggressive launch control, plus the Smartflash app lets you revert to the standard engine map or totally immobilise the car should you want to. If you're a car thief browsing this for a new target, forget it.

This particular car is fitted with a few other bits and pieces from Mountune’s parts catalogue – a high-flow induction hose (£85) and throttle body elbow (£99), short-shift kit (£150) and beefier brakes (£1,295), plus a prototype intercooler and lowering springs. 

What’s it like?

The m235 kit doesn’t totally transform the ST – it’s not night-and-day different – but you certainly notice the extra pace. This is a prodigiously, amusingly quick car that pulls cleanly and doggedly through each of its six forward gears. It feels meaningfully brawnier than stock, with enough low-down shove that you could easily leave in third and still make rapid progress cross-country. Such brawniness from such a small car with only a 1.5-litre, three-cylinder engine under the bonnet is almost absurd. There is no way you need any more performance than this in a daily driver. 

Sounds interesting, too. Louder than stock with more pops and crackles. Yes it’s all a bit forced and for some will be a bit much, but if the semi-skimmed 911 grumble doesn’t make you smile then you have no soul. Besides, it adds to the sense of speeeeed.

Shut up and take my money.

Quite. While we only drove Mountune’s demo car for a day, the kit doesn’t even seem to affect fuel economy all that much.

We’d probably leave the suspension – the ST is firm enough, but Mountune’s springs feel stiffer still and we reckon you won’t get the benefit of the lower centre of gravity et cetera unless you’re into your track days. For British B-roads – the ST’s natural habitat – the standard setup is fine.

Better to have more stopping power than you need, so we’d be tempted to go for the brakes. That said the standard stoppers are more than adequate, and £1,295 is a big chunk of change. Again, maybe another one for the track day enthusiasts among you.

Meanwhile the short-shifter is an improvement on the standard car’s gearbox and relatively cheap at only £150. Still not brilliant, but does make the ST feel racier.

So what’s the verdict?

The Mountune’d m235 Fiesta is a very good car, that’s for sure. Brilliant for all the reasons a stock ST is brilliant, but with more punch and a more amusing exhaust note. £800 isn’t silly money - the ST's trademark blue paint is a £750 option from the factory, remember. If I’d been running a Fiesta ST for three years (the earliest Mk8 Fiesta STs are a little over two years old at the time of writing) I’d be seriously tempted.