It's easy to forget that until a couple of years ago Ford did not have a decent, up-to-date diesel engine to put into its Mondeo range. That grim situation was very successfully attended to with the introduction of the splendid two-litre TDCi turbo unit, which has now been upgraded to match the Euro IV emissions regulations coming into force at the beginning of 2005.How this was achieved is of course Ford's problem rather than ours, but for the record it involved a new Garrett turbocharger, some work on the pistons and a whole heap of modifications to the fuel injection system.The result, according to Ford's figures, is that the TDCi now performs better than it did, as well as producing better overall emissions (even though the CO2 figures are marginally higher). Maximum power is the same as before at 128bhp, but there are improvements in the lower half of the rev range which make the Mondeo a little quicker off the mark.Not that you would really notice them unless you did a back-to-back test with a 2003 spec car. And that also applies to the mild updating of the interior and exterior design - only a particularly keen Mondeo-spotter would immediately notice the differences.So the broad description of the Mondeo's design is the same as it used to be: a neat if rather sharp-edged exterior, an interior which manages to look slightly low-grade regardless of how well equipped the individual model really is, and finally (in this particular case) a smart conversion to estate format which if anything makes this version look better from the rear than the saloon or hatchback equivalents.The principal appeal of the estate is of course the extra luggage capacity. With all seats in position this Mondeo has 540 litres of fresh air available, which is about 100 more than the saloon and hatch can carry if they use standard spare wheels (space-saver wheels release about half the difference).Fold down the rear seats and the estate's capacity increases to 1700 litres compared with 1370 for the hatch. You even get an extra 4cm of rear headroom.There's not much of a downside to this. Interior noise levels, which are inevitably higher in an estate than a saloon, are still quite subdued, though in general the Mondeo's suppression of engine sound is not class-leading.Where the Mondeo range does score is in its reasonably sharp handling (by the admittedly moderate standards of the sector - the Mazda6 is by some way the best of the bunch). It's a little too cumbersome in town, but on country roads it performs in a way which still makes me wonder how Jaguar lost the plot using the same platform in the front-wheel drive X-Type.The estate, with its large expanse of empty space between the rear suspension points, loses some of this ability, but the only significant issue is a slight tendency for the rear end to skip if it encounters a mid-corner bump.As with the CO2 statistics mentioned earlier, Ford's own fuel economy figures for the new TDCi engine are actually slightly inferior to those for the Euro III version, but it's still possible to travel over 500 miles per tankful. That's largely due to a very high sixth gear, which gives about 37mph per 1000rpm.This is by no means an industry record. In their most high-performance forms, the turbo diesel SEAT Ibiza and Skoda Fabia are more highly geared still. But they're much lighter cars and their top gears are useable almost all the time. Realistically, the Mondeo can't be asked to do less than 60mph on a level road in top without tripping over its shoelaces.Point it down a motorway, though, and the Mondeo becomes a most effective high-speed cruiser, wafting along at barely twice the engine tickover speed, the diesel rattle a distant memory, and operating on a mere dribble of fuel. There's a lot to be said for this car in many situations, but it's as a dependable long-distance operator that it really scores.Second opinion: Yes, the current Mondeo seems to be a car which is maturing nicely rather than getting left behind, and there's simply no arguing with the fact that it's the best-selling diesel range in the UK. Compared with a number of apparently classier rivals, the estate offers noticeably more rear seat and load space. Interior detailing in the 2004 Zetec is quite neat, and there's just the right amount of brightwork. The Mondeo cabin does look better with leather trim rather than the Zetec's standard cloth upholstery, which might show signs of wear quite quickly. The gearing of the test car was certainly close to stratospheric. I regarded it as a four-speed vehicle in town traffic, a five-speeder in anything up to a 50mph limit, and a six-speeder only above that. There was no point in letting it lumber along in too high a ratio. But when you want it, there's formidable torque - 243lb/ft from 1800rpm. And what a long-striding motorway machine! All things considered, I certainly wouldn't swap the six-speed manual box for the automatic option. Ross Finlay.