The ZT 190 will, for the time being, be the most powerful and expensive MG you can buy. The 190 tag refers to the 2.5-litre 24-valve KV6's output in PS, which is 187bhp in old money. It costs from ΂£20,495, which puts it in between Ford's Mondeo Zetec-S and Jaguar's X-type 2.5 Sport, so it had better be good.

Talk to the engineers and marketing men and you sense that this, the ZT, is the car they are most proud of. With the smaller MGs it was a case of making the best of what they had but with the ZT they had a much more modern platform on which to build. The result is a car by which the potential of the MG resurrection can be determined.

First impressions are encouraging. Stripped of its chintzy chrome and wearing purposeful 18in alloys, the 75 becomes a handsome, imposing shape. Metallic silver suits the ZT especially well - bold, solid colours bring with them an element of clumsiness.

The interior has also benefited from a thorough rework. Gone are the olde worlde cream dials and plump armchairs, replaced by silver-faced gauges and supportive sports seats. The steering wheel is rather big but adjusts for both reach and rake, so it's easy to find the ideal driving position. Wall-to-wall wood has been ditched in favour of high-quality plastics - only the metal-effect facia-inserts spoil the ambience, but at least MG has avoided mock carbonfibre. Overall it's a convincing makeover but what's it like to drive?

Pretty good but not great, is the answer. The 75's strong points remain, namely superb ride quality and refinement. Those 18in wheels haven't compromised the ZT's ability to parry bumps with remarkable deftness, yet where a 75 would get wallowy and remote, the ZT maintains its tight body control and planted feel. Crests and unexpected dips also fail to ruffle the ZT. It never feels ragged or likely to hit its bump-stops which means you can keep up a good pace over difficult roads. The huge tyres also mean that traction is very good. Short of dumping the clutch at high revs, you'll very rarely spin the front wheels. Wet roads would obviously present more of a challenge but I'd be surprised if the ZT lost its composure. Add in a slick if slightly rubbery gearshift and tireless brakes complete with EBD (Electronic Brakeforce Distribution), and it all looks good for the ZT.

Unfortunately the rest of the driving experience is a bit underwhelming. Torque-steer has been virtually eradicated - the closest you'll get is a momentary tug when changing flat-out from first to second - but steering feel has suffered as a result. It's not totally numb, just heavily filtered and vague around the straight-ahead. The big tyres probably contribute to an artificially heavy feel which seems at odds with the effortlessness of the rest of the package.

Though the ZT is undoubtedly well-built and solid, the feeling that it's a heavy car dogs your progress. It never feels quite like you've got 187bhp under your right foot. The V6 is slow to rev and lacks low-down torque; you find yourself willing it on, hoping it's a firecracker at the top end. It isn't, though it does pick up beyond 4000rpm. Part of the problem is that it's so refined that the impression of speed just isn't there. Fine for a 75 with sporting pretensions, but not so good in an out-and-out hard-edged MG sports saloon. In fact, the ZT feels like a Mondeo Zetec-S in many respects, only a bit quicker. Which is OK. I just wish it was a bit more exciting, a bit more evo.

MG is pitching the ZT 190 into an incredibly competitive sector inhabited by big names with big reputations. The fact that the ZT is worthy of comparison is an achievement in itself. It would certainly give a Mondeo V6 a run for its money, although X-type and BMW 3-series may be a step too far. Maybe early next year, when MG launches rear-wheel-drive, V8-powered ZTs toting 260 and 375bhp, it will find the edge we crave. Until then the ZT just misses the heartland of evoness.