Flushed with the success of its recent batch of hot hatches, Ford has once again decided that a Mountune badge would look rather nice on the rump of its hot Focus and Fiesta ST models.

In case you didn't know, Ford's association with Mountune goes back to the previous generation Focus and Fiesta.

Critically acclaimed for offering more bang for your buck than anything else for the same respective prices, it also opened the eyes of many to the underlying potential of the cars. In short, they were easily a match for whatever else was flavour of the month.

Fast forward to today and, concentrating on the Fiesta, the prospect of a 215 horsepower supermini for less than £20,000 is a distinct possibility.

For a few hundred pounds you can lift the Fiesta ST's already ample 182 horsepower tally to the heady heights of 215. Crucially, torque is another beneficiary of the upgrade, with 236lb ft of the stuff instead of the regular car's 214lb ft figure.

Mountune works its magic by installing a remodeled airbox and high-flow filter plus some clever electronic calibration to squeeze more out the car's 1.6-litre turbo motor.

And this is no backstreet modification either, with the fully guaranteed service available at one of 120 Mountune-appointed Ford dealers if you have a spare hour to kill.

It's well known that the current base Fiesta ST is a little special, even by Ford's own high standards. However, with the Mountune kit the diminutive hatch is transformed.

Although already a feisty machine in a straight line, in Mountune guise there's a noticeable extra shove in the back when you accelerate with conviction.

And while straight-line speed is a great pub bore topic of conversation, the Fiesta's ability to go around corners should have you steadying your pint-holding hand.

Despite the extra power liberated by the upgrade, the Fiesta ST's other mechanical bits remain standard, which makes the overall experience all the more impressive.

True to form, the ST stops, steers and goes with all the aplomb of something a lot more expensive. Ford's engineers have form for producing rewarding cars for keen drivers, but the behaviour of this upgraded Fiesta proves just how good the base car really is.

At a time when fancy electronics and flappy paddle gearshifts are taking over, the Fiesta's simplicity shouldn't be dismissed. The car's direct, weighty steering and slick manual gearchange would impress even the most tech savvy young driver.

Everything else about the car is classic Fiesta, which means a comfortable cabin and good level of standard kit. Opt for the high spec ST2 and you can have chunky sports seats plus a well specified infotainment system.

And while such toys are unlikely to overshadow the car's on-road performance, they will do much to help you pass the time during the daily commute.

Not that you'll need distracting from the driving duties as, unsurprisingly, Ford scores another jackpot with the way the car behaves for the other 90% of the time.

It might be a hot hatch but the Fiesta ST's compliant ride and high levels of cabin refinement allow you to relax when going to the shops. For a car with so much potential, and so many horses under its bonnet, it behaves like the proverbial pussycat around town.

With Ford getting so much right with the Fiesta and Mountune finding the car's performance sweet spot with its simple and low-cost upgrade, you'd be forgiven for thinking there must be a catch. The good news is there isn't one, which means if you can spare the funds it would be criminal not to take advantage of this upgrade.

FACTS AT A GLANCE

Model: Ford Fiesta ST Mountune, from £16,995 plus £599 for Mountune tuning pack.

Engine: 1.6-litre petrol unit developing 215bhp.

Transmission: 6-speed manual transmission as standard, driving the front wheels.

Performance: Maximum speed n/a mph, 0-62mph 6.7 seconds.

Economy: n/a mpg.

CO2 Rating: n/a g/km.