Citroen C6 3.0 HDI : TECHNICAL EXCELLENCE

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Can the 3.0-litre V6 diesel engine bring the Citroen C6 into the reckoning for more executive car buyers? Steve Walker takes a look.

Reviews of the Citroen C6 usually adhere to a familiar pattern; we'll call it `kind words and a caveat'. There's a lot to like about the French marque's executive saloon. It has admirably resisted the temptation to ape its German rivals. It prioritises comfort over sporting excess. It's a little bit quirky. Similar points are generally raised in any evaluation of the car and just when the reader thinks a resounding thumbs-up is on the cards, the big `but' arrives like an anvil dropped from a passing airliner. The C6 is a Citroen and so doesn't have a premium badge and as a result, very few executive car buyers will even consider it. Could this problem be addressed by the fitment of an engine with cast iron executive pedigree, an engine like the 3.0-litre V6 HDi?

Don't hold your breath on the 3.0-litre HDi diesel engine catapulting the C6 to the top of the sales charts above the BMW 5-Series and Mercedes E-Class. That's not going to happen but there's a strong likelihood of this advanced oil-burning unit enhancing the already impressive C6. Maybe it will even give its rivals something to think about. The unit is a development of the 2.7-litre twin-turbo diesel that the C6 was launched with. Like that engine, it's been developed in a partnership between PSA Peugeot Citroen and Jaguar Land Rover. Jaguar's XF has proven itself well capable of doling out bloody noses to the Germans in the executive car class and this selfsame 3.0-litre diesel engine is a key part of its offering. So is the C6 3.0 HDi due a similar surge in credibility? The engine is a 3.0-litre HDi with a pair of turbochargers helping it to develop 240bhp. More impressive still is the flat torque curve that sees the 450Nm maximum output produced from 1,600rpm all the way up to 3,600rpm. This is a highly advanced engine with aluminium cylinder heads, four valves per cylinder, double overhead camshafts, a common-rail fuel injection system delivering fuel at 2,000 bar through piezoelectric injectors, two low inertia turbochargers and an exhaust gas recirculation system. Owners of this C6 should feel in no way inferior to drivers of the top six-cylinder diesel models in the executive sector.

"Citroen's C6 now has a truly world-class engine on its books."

Citroen's flagship is not the executive car to choose if you regularly find yourself in the mood to give your favourite section of B-road a good mauling. Instead, it's a car in which to take things easy and enjoy the impeccable ride quality served up by the Hydractive self-levelling suspension. The twin turbochargers on the 3.0-litre HDi engine help it gel with the reserved road manners of the C6. The system works to produce a smooth and progressive supply of torque from low in the engine range, eliminating the lag and lunge often associated with less sophisticated diesel installations. The C6 is a commendable piece of work on the part of Citroen's design team. The shape is resolutely modern but at the same time, the proportioning (rather than the detailing) is reminiscent of classic Citroen shapes from the past. The elegant arc of the roofline and the long front overhang are redolent of the old DS and SM models, while the short rear overhang and low slung back end reprise some classic Citroen themes. The company claims that the target was to develop a car with the stance and presence of a limousine but with the chic silhouette of a coupe. They may just have succeeded. A long wheelbase and low slung posture are quite unlike anything else on the road at the moment. The windowline across the curve of the roof arch is picked out with a subtle chrome strip - a clever aesthetic trick that helps visually elongate the car. The frameless glass of the doors also helps here, removing the need for bulky door pillars that would otherwise break up the impact of the remarkable glasshouse. The interior feels like that of a premium brand product, if not one of the real top dogs in terms of fit and finish. Without doubt, it gives us a different perspective on what Citroen can achieve in this regard. Space in the rear is extremely generous and there's a very nice detailing to keep passengers in the manner to which they are accustomed, but the boot isn't quite as capacious when compared to other models in the class. The £36,000 price tag instantly looks like a lot of money for a Citroen and this is where much of the C6's good work is undone. It's possible to buy an Audi A6 or a BMW 5-Series with a similar engine for similar money or even a bit less, while the Jaguar XF with an identical powerplant also undercuts the French offering. Citroen does include a very generous equipment list as standard and specifying these premium brand models to an equivalent level would see them jump dramatically in price but image-conscious buyers will take more persuading than that if they're to choose a Citroen over a premium badged alternative. Much will depend on the kind of discounts that are available at Citroen dealers. Packed with technology, the C6 features a head-up display that projects speed and navigation instructions onto the windscreen. There's also a comprehensive driver's information system, an electronic parking brake, the innovative lane departure warning system, directional Xenon headlamps and a speed limiter. The 3.0-litre HDi engine is offered only in range-topping Exclusive trim which also includes electric seats, satellite navigation, sunblinds and a JBL stereo. Economy is good but residual values will be a big concern. The 3.0 HDI C6 can return 38mpg on the combined cycle with CO2 emissions 195g/km. Environmental performance is helped by a standard diesel particulate filter that traps harmful particulate matter before it leaves the exhaust system. The D word is a constant thorn in the side of any manufacturer that ventures in to the executive saloon sector without a respected premium badge to slap on the nose of its entry. As a result, the C6 depreciates like a snowmobile in the Sahara. It's an unfortunate fact of life that helps to make Citroen's flagship a stupendous used buy and a sometimes sobering new one. Citroen's C6 now has a truly world-class engine on its books. The French executive express is an unusual and rewarding vehicle in a sector characterised by conformity and with the 3.0-litre HDi diesel engine installed, it looks an even more viable proposition next to the premium brand elite. The problem is that this high-tech powerplant bumps C6 prices up to a level where it's challenging the 5-Series, E-Class and A6 on a level playing field. In this company, it's doubtful whether the lack of a premium badge and shaky residual values can be compensated for by the generous equipment levels of the C6. Citroen has only ever expected modest sales levels for its flagship model in the UK and while the 3.0-litre HDi engine will make it a notably better car, it's unlikely to provoke much of a spike in customer interest. That's great news for executive buyers who want something different and are prepared to seek out one of the most exclusive models out there.

Facts At A Glance
CAR: Citroen C6 3.0 HDi
PRICE: £36,695 - on the road
INSURANCE GROUP: 17 [est]
CO2 EMISSIONS: 195g/km
PERFORMANCE: 0-60mph 8.5s / Max Speed 155mph [est]
FUEL CONSUMPTION: (combined) 38mpg
STANDARD SAFETY FEATURES: Nine airbags, ESP, ABS with EBA and EBD, active bonnet, lane departure warning system.
WILL IT FIT IN YOUR GARAGE?: Length/Width/Height 4908/1860/1464mm