Let's get one thing out of the away before I start: I happen to like high-performance, small-capacity cars. So I'm biased already. The reason is simple. In this speed-restricted, speed camera-infested, road traffic-congested island we call the United Kingdom you can get closer to the limits of a well-tuned small-capacity engine than you can with some multifariously-cylindered, force-fed, high-capacity lump when driving on quiet public roads.Or put it another way, the maximum speed limit on Government roads is the same whether you are driving a Ford Fiesta ST Mountune or a Porsche 911 Turbo. On that basis, the only real difference is in the time it will take to get you from rest to 70mph. In this case, the difference is 5 seconds. And what can you do these days in only 5 seconds? Read the Sun? Fall out with the wife? So it's hardly worth bothering about then, is it?Some of the power purists might then take up the cross-country argument that their supercar's better handling will cut journeys times on A and B roads. That may be true, but if you're not able to stretch the beast and seek out its limits then the driver satisfaction level will be much lower than in a pocket rocket which regularly trips the adrenalin pump when trying to match the entirely capable aforementioned supercar.So if that's the case for fast shoeboxes, how does this latest version of the Ford Fiesta ST Mountune measure up? First of all it's more than a chip-shop job, and there are two versions. There is a Stage 1 option which increases the basic horsepower from 148bhp to 163bhp and a Stage 2 version which ups the power to 183bhp.The Stage 1 oomph comes from a revised air induction system and new exhaust with subtle changes to the ECU. The faster package adds new camshafts and valve springs to help create the extra grunt. At £1435 and £1838, both plus fitting costs, the dealer-fit changes ain't exactly cheap but you do get the advantage of a 12 month/12,000 mile warranty which can be extended up to 3 years/36,000 miles.And if you're feeling flush there are a few other tasty options including a KW suspension kit (£605) and the extravagant leather and suede Recaros at a completely unjustifiable £1950 – but still ultimately desirable!Outwardly the deeper front airdam and the new 17" alloys set the Fiesta apart from its standard siblings, but the other big giveaway is the large-bore exhaust sticking out the back. An altogether more attractive and substantial item then many of these cheap aftermarket bolt-on drain pipes that can be heard droning long into the night around the nation's housing estates.So if the looks are subtly different there is nothing subtle about the new performance levels. Each gearchange and every blip of the throttle is accompanied by an urgent bark from the throaty exhaust. Even more intoxicating are the accompanying gurgles and backfiring on the over-run.As for the gearchange, it's more tactile than Claudia Schiffer giving you a rubdown with a bath sponge. And with the traction control switched off it was more energising than poking a wasps' nest with a stick. To hell with going to work, I went looking for twisty roads and hairpins.The standard ST is not really quick and although this new 183bhp lump is much quicker, it is just fast enough to have fun without being nervous. Mind you, that might have something to do with the 8000 miles on the test car - there could be a little more to come when it finally loosens up.With the KW suspension kit fitted, the ride is choppy at low speed, but smoothes everything out when working hard. It has also removed the stilt-like nervousness of the previous car and feels planted at all times, especially on the turn-in. The new set up has brought back the dart-like tendency of previous successful small Fords.It will willingly rev to 6700rpm (although the standard 6500rpm revcounter is retained) but cruising at anything over 2000rpm reveals why modern youth must travel everywhere with the ICE turned up at full volume. It's to drown out the big-bore exhaust which booms quite noticeably when cruising, especially around the mid-rev range. But at 2000rpm in fifth gear (there's no need for a sixth with this flexibility) the car will be cruising at just over 40mph - quietly!I suppose the telling question is, would I have one? In a word, no. It's a young person's car, the boom from the exhaust would eventually drive me up the wall, and the Recaro seat sits too high on its subframe, so although it was comfy, my napper was a bit too close to the roof and I had to peer under the top of the windscreen.Otherwise it would be the perfect second car for an old man. A bit of fun at weekends reliving past times and revitalising the bits that would otherwise wither away. Yes I loved it, but I wouldn't have it. And yet, show me a switchback and I could be sorely tempted.