Motoring: And pop goes the diesel: Great diesels such as the Citroen Xantia are really catching on, says John Simister

With most cars, petrol power is normal and diesel an aberration. Start up a Vauxhall Cavalier, for example, and you expect the smooth hum of a petrol engine, not the clatter of a diesel.

Things are different in a Citroen Xantia. More than half the Xantias on our roads are diesel-fed; it is the petrol-engined version that is more likely to raise an eyebrow. The reason for this is that the diesel Xantia, especially the turbodiesel, is such a complete car. It feels as though it was designed around its engine. Which, indeed, it probably was.

The arrival of such models has helped diesels to capture more than 30 per cent of the new-car market in Britain. Fifty per cent of new Citroens and Peugeots are diesel-powered. But the acknowledged experts in the manufacture of popular diesels are beginning to worry about being typecast, and that the prestige of their high-performance, petrol-powered cars may suffer.

No one, however, should apologise for the Citroen Xantia turbodiesel. Here is a car that will top 110mph, reach 60mph from a standstill in 12.7 seconds and still return an easy 40mpg or more. And if these figures leave you unimpressed (as those for outright speed may), consider that it does all this with a relaxation and a refinement which eliminate driver stress.

The engine rattles a bit after a cold start, as most diesels do, but the noise barely permeates the Citroen's soundproofing. Thereafter, you will hear little more inside the cabin than a quiet hum, like a petrol engine's but deeper in tone. You can tell it is a diesel, of course, but it does not matter.

As well as being quiet, particularly at motorway speeds, the Xantia proves muscular in the higher gears. You can nip past things in fourth that would call for third in a similarly powerful (92bhp) petrol car, and you seldom need to work the engine hard. Even if you wanted to, you could not coax it much beyond a relaxed 4,800rpm. So you shift up a gear instead, and let the 1.9-litre engine's hunky 148lb/ft of pulling power - that is more than a BMW 320i can manage - do the work.

Another aspect of this engine's easy, friendly nature is the way it pulls smoothly from low speeds. Too many turbodiesels ignore your demands until the turbocharger spins up to speed, so you have to change down a gear. Not this one: the 'turbo lag' is minimal, with power building up strongly and controllably instead of bursting through in a sudden torrent. Such a diesel does good things to your driving. Because you are more relaxed, you become more tolerant of traffic; you arrive fresher and return in upbeat mood.

But it is not just the engine that is special. The hydropneumatic suspension makes you feel as though you are floating on fluid - which you are. It soaks up coarse road surfaces wonderfully and smothers bumps so unobtrusively that you would swear the council had resurfaced the road since you last travelled it.

The dynamics, however, are not perfect. The nose rises and falls as you accelerate and slow down, which can make some passengers feel queasy. And they will feel queasier still until you learn to modulate the brakes, which have a snatchy, anaesthetised action compared with rival cars' systems.

A similar problem afflicts the steering, which feels disconnected from the front wheels until you have turned the wheel well away from straight ahead. A fast, gentle bend can have you wondering momentarily what direction the car is taking - which is unsettling. And the Xantia feels less than reassuring on slippery surfaces, because its steering gives no hint of the grip beneath the front wheels. Fortunately, its roadholding is tenacious, and its handling precise in tighter corners.

Those familiar with the Xantia's predecessor, the Citroen BX, will be surprised by the car's feeling of quality. It is well made, with good materials, a solid feel and a fine paint finish. Add to this the comfortable cabin (copious legroom and wide doors in the back), and you have a car that should please passengers as much as it does the driver (who has to put up with lack of thigh support in driving seat).

Steering and brakes notwithstanding, the Xantia TD is a fine car. (In fact, the whole range - with diesels in LX, SX and VSX trim - is outselling Rover's 800 and those made-in-Britain Japanese cars, the Nissan Primera and Toyota Carina.)

And there are two more reasons for falling in love with it, as I have done. The first is that, with its crisp form, stub tail and handsome detailing, it wins the family car beauty contest by a mile. The second also has to do with distinctiveness: it has not lost the more useful elements of Citroen eccentricity.

Anyway, how can you fail to fall for a car that rises on its self-levelling suspension when you start the engine, sinks to the ground shortly after you switch it off, and greets every additional passenger with his or her very own suspension-height readjustment?

SPECIFICATIONS

Citroen Xantia SX TD, pounds 14,200

Engine: 1,905cc, four cylinders, 92bhp at 4,000rpm. Five-speed gearbox, front- wheel drive. Performance: top speed 110mph, 0-60mph in 12.7 seconds. Fuel consumption, 40-45mpg.

COMPARISONS

Audi 80 1.9 TD, pounds 14,999

This cheapest Audi diesel - slower, noisier and less well equipped - looks poor value compared with the Citroen. The direct-injection Tdi offers improved economy and power - at pounds 16,028.

Ford Mondeo 1.8 TD GLX, pounds 13,550

An airbag fitted as standard and a dealer in every town cannot make up for the Mondeo's coarser, lazier engine and unimpressive rear cabin space. Steering and brakes outrank those of the Citroen, however, and overall comfort is on a par.

Peugeot 405 1.9 SRDT, pounds 14,675

Xantia's closest rival is another Peugeot/Citroen group product, but matches the same engine to a saloon body instead of the Xantia's hatchback. The 405's handling and ride are first-class, but its design is a lot older.

Vauxhall Cavalier 1.7 TD GLS 5-door, pounds 13,230

Japanese Isuzu engine gives the Cavalier fair performance but, like the Mondeo, it is a rather coarse unit with poor response at low speeds. Fine facia design apart, the Vauxhall is a fairly average car.

(Photograph omitted)