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Ride, agility, fuel economy, equipment, versatility

Room for improvement
Indecisive automatic, rear seat can be cramped

THE turbo-diesel Citroen C5 HDi treads a path followed by only a handful of passenger cars in Australia, but there are plenty of good reasons to consider the oil-burning option.

Number one is fuel economy, which is quite astonishing for a vehicle of this size number two is that there is no penalty to pay either in terms of purchase price (it's actually slightly cheaper than the automatic four-cylinder petrol-engined C5), performance or operational noise levels.

The C5 HDi is a new-age turbo-diesel, which means it suffers few of the shortcomings normally associated with oil-burners but still picks up the advantages.

The engine's appearance in the new mid-size Citroen is entirely appropriate given the French car-maker's slightly off-centre tradition. It adds another dimension to a car that tries to be slightly different to the mainstream prestige-class cars, particularly in the area of aesthetics.

With its slightly slabby combination of MPV, hatchback and sedan looks, the C5 tends to polarise aesthetic opinions, but the packaging can't really be argued with and the Citroen comfort factor is certainly there.

Other aspects measure up too. The pricing puts it smack in the middle of the entry-level prestige class, the equipment is right on the mark and the availability of powerplants covers all bases.

The torquey and economical turbo-diesel adds an extra something that can only be matched by two other entrants in this class - Peugeot's 406 HDI sedan, which uses the same engine as the Citroen, and Mercedes-Benz with its C220 CDI.

All C5s get essentially the same basic gear, which means all have "Hydractive" automatically adjusting hydraulic suspension, anti-lock brakes, a nearly-full complement of airbags, air-conditioning, rain-sensing windscreen wipers, trip computer, cooled glovebox and, just to throw some confusion into the category, a five-door hatchback body that Citroen calls a sedan.

Nobody thinks that is a good idea in the prestige class any more, which either means everybody else is wrong, or that Citroen is working to a different agenda. Certainly, the way things work out with the C5, there are few disadvantages to take note of - and it even looks much like a sedan.

Automatic stability control does not find its way into the Citroen, like it does in an increasing number of prestige competitors, so buyers need to be convinced that Hydractive gives compensating benefits.

A dimensional comparison with the Xantia shows the C5 to be the bigger car, with a few millimetres of advantage in all directions - particularly height, where it towers over the outgoing car by 7.6 centimetres.

In fact it does much the same to most of its prestige competitors even though other dimensions are roughly in the same ballpark - length, width and track dimensions are pretty normal although it does have a substantial wheelbase compared to the rest.

This explains why the C5 feels quite large on the inside, while the tall stance tends to create proportions that make it appear quite small from the outside until parked next to another prestige competitor.

The reality, from the driver's seat, is that the Citroen feels airy, almost MPV-like. Its A-pillars swoop towards the front of the cabin and the back seat looks commodious and quite distant, promising good legroom.

That impression tends to fade away should you try to add tall front-seat passengers into the mix, but with a bit of compromise the C5 can be a very comfortable four-seater and a reasonably acceptable short-distance five-seater.

Like most Citroens, there is a lot to get your head around when you first approach the C5.

Once you've dealt with the looks, explored and fiddled with the interior, jumped in and out of all seats and examined the numerous bins and cubbies (the lidded door bins are handy, as are the slide-out drawers under the front seats) it is time to confront the business of driving it and here a few challenges are presented.

The first thing you notice is the feeling of being located low and snug in the cabin. Driver and front passenger are able to set their seats to the appropriate height, but there is still the definite feeling of being inside, rather than on top of the car.

Up front, driver and passenger are located on well-shaped and supportive seats. The HDi misses out on the captain's chair armrest seen on petrol-engined C5s, but in the back there's a comfortable split-fold bench arrangement with a fold-down ski port/centre armrest.

There is no question this is a car designed to pamper although, as we said a little earlier, rear seat legroom is entirely dependent on the greediness of those sitting in the front. With just a little compromise, everybody is happy - even if everybody happens to be more than 180cm tall.

A minor negative is that for some, the amount of cushion angle adjustment available in the front leaves the passenger with a feeling of wanting a little more.

The driver is presented with a sweeping, stylised instrument panel - nothing particularly unusual these days - but down on the centre console sit two buttons that are the key to the distinctive character of this car.

These are the controls that allow the C5 to be lifted high enough to elegantly clear rocks or bumps that may be in its path, or to lower it into a ground-hugging position to assist loading, or the hitching of caravans or trailers.

Selecting an extra-high position causes the C5 to elevate itself enough for easy changing of tyres. The Hydractive system also reacts to existing circumstances, firming up if the car is being flung at a tight corner, then reverting to soft and cushy in a straight line.

This is the third iteration of Citroen's Hydractive suspension and is a simplified, low-maintenance yet more feature-loaded system than before.

In V6 and petrol four-cylinder models, but not in the HDi, selectable sport/comfort modes allow the driver to choose between two different types of ride/handling characteristics. The system, as in the Xantia, uses a central hydraulic fluid reservoir that feeds four suspension spheres - one for each wheel - that operate as the springing medium and also allow variations in ride height.

The difference in Hydractive 3 is the adoption of two extra spheres - one front and back - that also vary the overall stiffness of the system.

Hydractive also uses electronics to give a certain degree of "active" suspension control. In order to allow the system to react quickly to changing circumstances, it measures variations in ride and height and suspension movement, steering wheel angle and the speed at which it is turning, activity at the accelerator pedal, engine speed, brake pedal pressure and road speed.

The pure mechanics of the suspension are much the same as the Xantia, with MacPherson struts at the front and an aluminium crossbeam at the back using cast-iron trailing arms and self-steering geometry.

On the road, all this gives the C5 its distinctive Citroen character - although it must be said the characteristics are not wildly different in many ways to some more conventionally suspended cars, particularly French ones.

The car proceeds with an easy, floating style that beautifully dispenses with undulating surfaces yet tends to make it feel a little unsure on some high-speed bends.

The surprise comes when the C5 is thrown at a tight corner. Remembering how it felt on those wide-open sweepers, it might be reasonable to expect the Citroen to lose itself in a mess of wallowing, lurching, scrubbing understeer but, no, the C5 merely has a quick think, alters suspension setting appropriately and swiftly and surely swoops its way through. No understeer to speak of, very little bodyroll and no loading up of the steering.

Then, of course, there is the way the car automatically drops to its lowest ride height at speed, although in most parts of Australia this will have little relevance because it happens above 110km/h. Only Northern Territory drivers will be able to appreciate the fact that it lowers at the front by 15mm, and the rear by 11mm, assisting aerodynamics (which are strangely nothing special with a coefficient of drag of 0.30) and straight-line stability.

More useful are the assured constancy of ride height regardless of load, the 13mm increase in ride height available at speeds up to 70km/h for traversing rough roads - where the suspension thrums and drums in a muted sort of way - and the ultra-high setting which can only be used when the car is stationary and is handy for changing wheels.

At night, there's a Saab-style night panel that dims all but vital illumination at the flick of a switch.

The automatic windscreen wipers are a bonus too, as is the ability of the windows to close automatically if it starts raining, while the external rearview mirrors are heated for quick demisting on frosty mornings.

And what about the engine/gearbox combination? How is the C5's superlative suspension behaviour supported by the all-important considerations such as the ability to accelerate swiftly, and to cruise silently and comfortably? And how about the ability of the braking system to bring all this to a stop swiftly and surely?

The turbo-diesel may produce only 82kW, but this output comes at an almost truck-like 4000rpm, while the maximum torque of 255Nm is developed at an equally impressive 1750rpm. This means the engine is ready to go once it has climbed not far above idle.

The downside is that the power band, though quite wide, falls away noticeably once engine speed reaches 4000rpm and, in manual turbo-diesels, this means a change of driving style. That's one of the reasons turbo-diesels and automatic gearboxes are a match made in heaven, as the car's electronic systems do all the work.

In the case of the HDi - and maybe it applied just to the test car - the interface is not always harmonious.

The four-speed auto was at times extremely reluctant to downshift, either in throttle-on or throttle-off situations.

In the latter, the CDI would shudder alarmingly as it came to a stop and the transmission remained determinedly locked in top gear, almost as if it were a manual and the driver had forgotten to depress the clutch. Similarly, it would remain steadfastly in top gear on a steep upward incline, stretching to ridiculous limits the point where kick-down occurred.

The reluctant downshifting behaviour could always be countered by using the sequential facility, or by selecting the "sport" mode - although the latter favours higher engine rpm and noticeably affects fuel economy.

That was the downside - the engine and transmission otherwise worked together well, with smooth-enough gearshifts and plenty of verve when accelerating away from a standstill.

It may not have the top-end surge of the V6, but the HDi is more than capable of fending for itself either on the open road, or in cut and thrust around-town driving. And although some diesel clatter is always evident, it is generally quite muted.

The bottom line with the HDi is, of course, fuel economy - and here the Citroen delivers handsomely. Factory figures suggest only 8.9 litres of diesel will be used every 100km, while out on the highway the figure drops to a ridiculous 4.6 litres per 100km.

During the test, our car was driven mainly in urban situations and recorded averages around 7.8 litres/100km, which is far from shabby although not in the 1500km per tankful realms suggested by Citroen (the HDi inexplicably has a slightly larger 68-litre tank than the petrol-engined versions - 66 litres).

The other important aspect of the C5 - bringing the whole thing to a stop - is adequately catered for by an all-disc system with anti-lock, electronic brake force distribution and brake assist - which boosts pressure to help stop the vehicle more quickly in emergency situations.

The system certainly adds a secure dimension to the way the C5 feels on the road, although the pedal is too sensitive to light applications and requires some acclimatisation.

The HDi's steering is engine-speed sensitive compared with the V6's road-speed sensitive system and, to many, offers a better overall feel than the V6's sometimes artificial quality. It offers a little more weight at cornering speeds but is still light enough for easy parking (although the HDi misses out on the park-distance sensors fitted to the V6).

Overall, the C5 is a car that imbues feelings of confidence and security (front and side airbags are provided for front-seat passengers and there is a full-length curtain airbag to assist in side impacts) while it is also comfortable and practical.

The unique flavour is being progressively diluted, but at least there is still something different about the latest Citroen, both in its eclectic design themes and its dynamic behaviour, that will resonate with buyers requiring something a little above the ordinary.

And, in the C5 HDi, the hip-pocket will always be thankful when it comes to refuelling.