FRST

The standard model is exceptional, but the Mountune kit manages to improve on that with better mid-range responses and improved everyday flexibility.There’s more torque between 2,500rpm and 4,000rpm, so where before you may have had to change down, you can now just keep it in gear and ride the generous surge of acceleration....for us there’s no reason not to go for it. You’d be mad to miss out on the opportunity to make one of the best hot hatches in recent memory even better.

…The waters haven't been muddied too much, because you should just have it....In everyday driving, you notice several improvements. The extra torque means you can often sweep into motorway gaps without changing down. The extra power, meanwhile, chimes in with a hard-edged flare of combustion noise at 4500rpm, and allows you to get much closer to the red line before the engine runs short of breath in classic turbo fashion. That in itself makes flat-chat acceleration more exciting.Should I buy one? Absolutely. In a hot supermini class filling up with monotone and mediocrity, this engine kit makes one more distinguishing feature on a quite outstanding driver’s car.Truth is, you could spend £30k on a hot hatchback this year and end up not having as much fun... This is something of a masterstroke.

Mountune Fiesta ST - Top Gear Performance Car Of The Year 2013 - joint winner! …you drive the Fiesta ST with its mountune upgrade and realise that this is the blue-collar hero, a performance car for 2013's congested reality......It's not... outrageously engineered. What it is, is special. The Fiesta makes you happy....which makes it - for us - the performance-car bargain of the year.

The results are very amusing on the road. In fourth gear the little Fiesta will nail stuff with much more imposing badging....So for an extra £599 you can have a fully warrantied Fiesta that will do 0-100mph in 15.4 seconds. That is absolutely bonkers and could make life even more difficult for the Clio RS....They're both [Fiesta and Focus ST] cracking upgrades and it's hard to imagine ordering either car without them [mountune upgrade] given they don't invalidate the manufacturer's warranty.

Hit the start button in the ST and the 1.6-litre turbo four emits a delicious, deep burble that’s much louder and meatier than rather refined character this engine has in standard form.When you do succumb to temptation and mash the throttle… there’s a loud turbo whoosh that prompts head twitches and double-takes from by-standers ...Yet its performance is far from modest, and the upgrades have given it a sharper throttle that responds instantly – it’s bucketloads of fun to drive. You can really feel the extra urge, particularly in the mid-range...Most importantly, it hasn’t diluted any of the ST’s other talents... allowing you to use the extra poke through corners for even faster point-to-point coverage than the stocker.A winner? You bet. The Mountune Fiesta ST gives the class-leading hot hatch an even greater edge, without compromising any of the attributes that make the ST such a brilliant hatch. Add the fact that it’s discreet, affordable and backed by the factory, and it’s difficult to find a reason not to opt for it.