At the time of writing, the fastest Ford Focus you can buy new is the ST. Its two-litre four-cylinder EcoBoost turbo petrol engine produces a maximum of 247bhp, well up on the 225bhp of the five-cylinder second-generation version and miles ahead of the long-ago ST170. Even the original Focus RS, once regarded as just about the ultimate hot hatch, now looks almost insipid.As STs have become more powerful, they have also become better. I thought the ST170 was all over the place. The five-cylinder car was better-behaved, but more stolid than sporty despite its undoubted straightline ability. This latest model is the most accomplished yet.That's not to say that it couldn't be better. If you intend to use even a moderate proportion of the available power, you'd better be on a smooth, straight, dry road. Any deviation from that ideal should be considered a warning to go easy with the loud pedal.There is no problem with lateral grip - at speeds I was prepared to consider achieving on public roads, nothing suggested that either the front or the back end was anywhere near the limit. The limiting factor in the wet is traction, and in the dry it's torque steer. Even with a fairly modest throttle application you can quickly get to the point where the nose of the car is more influenced by the engine than by the steering wheel in its decision on where to point next.You may say that this sort of thing is inevitable when you put a 247bhp engine in a front-wheel drive car. But the Renault Megane Renaultsport and the Vauxhall Astra VXR are front-wheel drive too, and they have quite a bit more power, and neither of them suffers from torque steer to nearly the same extent as the Focus.None of this particularly makes me want to take the ST on a race circuit, but as a brisk road car it has a lot going for it. A small squeeze on the throttle at as little as 1500rpm is enough to make it nip away sharpish, much like a high-performance diesel, the steering and brakes are so responsive that they require very little effort to use, and the seats offer tremendous side support.As a way of covering the ground quickly with minimal stress and bother, then, the ST is greatly to be recommended. Just try to avoid the temptation of accepting all the engine has to offer and you'll be fine. You'll also, if my experience is anything to go by, average around 33mpg, which for such a quick car isn't bad at all.Focus STs come in six varieties, since there are three trim levels and, for the first time in history, a choice of five-door hatchback and estate body styles. The mid-range ST-2 hatch tested here costs £23,495 and is fitted as standard with part-leather upholstery, dual-zone automatic air-conditioning, a Sony audio, an auto-dimming interior mirror, ST branding on the floor mats and - absolutely my favourite piece of equipment right now, it being December and all - a heated windscreen, none of which is available on the £21,995 entry-level ST.The test car also had satellite navigation and a rear-view camera, but they were optional extras. They're standard, though, on the ST-3, which also gets full leather upholstery, bi-xenon headlights, keyless entry, rear parking sensors and powered folding door mirrors, and costs £25,495. Engine 1998cc, 4 cylinders Power 247bhp Transmission 6-speed manual Fuel/CO2 39.2mpg / 169g/km Acceleration 0-62mph: 6.5 seconds Top speed 154mph Price £23,495 Details correct at publication date