It\'s hard to knock the Fiesta. It\'s been around for 35 years, 15 million have been built and the current version is widely hailed as the supermini to beat across the globe. So how do you make the best better? That\'s a tall order to say the least, so Ford has adopted an evolution rather than revolution tactic to keep its hatchback success story up to scratch. Nothing has changed on the outside. Actually, that\'s not entirely true, as there are two new colours - Mars Red (scarlet) and Fashionista (a sort of pearlescent brown) - but that\'s all, and you can still order all the previous paint schemes. As for the interior, that\'s pretty similar, as well. It\'s still smart and well-built but the devil is in the detail or, rather, the options. A plush Sony DAB digital radio is now available and its presence adds a swish, piano black veneer to the centre console. Keyless entry, usually an option reserved for larger, more expensive cars, is also available. That\'s about it for the stuff you can see; otherwise it\'s all stock Fiesta on the surface. So what about the more than meets the eye bits? Truth be told, there aren\'t many of those, either. The single biggest and most significant change is the 1.6L TDCi ECOnetic diesel engine, which is now even cleaner. In its previous guise, it produced 98g/km of CO2, but Ford has managed to trim it down to 95g/km. As small as it may be, it\'s a step in the right direction, and allows the Fiesta to reach an average of 3.6L/100km. Of equal note is the fact that the ECOnetic engine is now available on more luxurious models. You could only it have it with a relatively basic Edge version until now, but Ford has extended it across the range, making it available on better specced Zetec and Titanium models. The idea is that buyers no longer have to put up with poverty spec cars if they want the best economy going, so you can have your cake and eat it when it comes to being green, cutting costs and enjoying your fair share of toys. Not that buyers in this region can even opt for diesel in their small cars. Because of the minutiae of the changes, it\'s virtually impossible to distinguish the latest Fiesta from its forebear by driving impressions alone. Don\'t mistake that for a negative comment, though, because the outgoing model was arguably the most enjoyable car to drive in its class. The steering is light, delicate and brimming with feedback, while the chassis deals with rough surfaces adeptly but still manages to communicate exactly what the car is up to. It\'s very easy to drive, but it\'s also a pleasure to drive fast, so it\'s appealing to those who just want a small, frugal car. Granted, the ECOnetic diesel engine isn\'t exactly performance car material but Ford has introduced a new, special edition version of the Fiesta known as the Metal. It\'s basically a tricked-up Zetec-S, with a 134hp 1.6L Duratec petrol engine rendering it capable of 0-to-100kph in 8.7 seconds. It also wears its fair share of bespoke exterior trickery, including black alloy wheels, chrome tailpipes and a lower ride height. It\'s neither fast nor extreme enough to qualify for an RS badge, but it\'s enough to keep the Fiesta appealing to more than just the eco freaks. So what\'s next for the Fiesta? Surely there will come a point where one of the world\'s most popular, successful and enjoyable superminis begins to reach the end of its tether? Not likely, because Ford already has plans for an even cleaner version in about a year\'s time. The next ECOnetic model will emit only 87g/km - and there\'s even an 89g/km Focus on the cards. The Fiesta\'s only real downside is that it\'s far from the most affordable supermini on the market, especially in ECOnetic guise. While Ford isn\'t alone in charging more for the cleanest models, budget rivals such as the Skoda Fabia Greenline II or Hyundai i10 Blue with similar, if not lower emissions, can be had for much less cash. That said, the cleanest models are priced competitively against direct rivals such as Volkswagen\'s Polo BlueMotion. What\'s more, you need to spend even more to find a hatchback with the same kind of all-round appeal as the Fiesta because it\'s just so good. It may not have experienced a major overhaul, but the best supermini has just got a little better.