Common rail carries fuel at extremely high pressure which is injected into the cylinder using electronic fuel injection, doing away with a hefty diesel pump and saving weight, while allowing for precise use of fuel, cutting CO2 emissions by 22%.Its clean credentials will be improved even further, the company says when the NOx catalyst is also fitted, cutting out 50% of nitrous oxides, although this is tied to the availability of ultra-low sulphur fuel.
Using the more advanced technology, the Xantia HDI, which stands for high pressure direct injection, produces 110bhp and 184lb-ft of torque, the same as the outgoing 2.1-litre turbodiesel it replaces. But it is the manner the HDI produces power that makes the difference. It provides nearly all its pulling power from 1,500rpm, 500rpm less than the 2.1 and also produces full torque lower down the rev range.
This extra flexibility, along with more efficient use of fuel from the injection system, means the economy figures are a world away from the outgoing model, 51.4mpg compared to the 2.1-litre's 40.4mpg in combined driving. It uses a two-stage injection process to cut down on noise and the high pressure of fuel injected into the cylinder ensures a cleaner burn from start-up, cutting out the telltale black puff of smoke sometimes associated with diesels.
Added to this, Citroen has extended service intervals from 6,000 to 12,500 miles to save on servicing costs. Total Xantia sales are expected to be about 20,000 for this year, with fleet sales making up the majority at 75%. Of these, diesel makes up about 60% of sales. Citroen executives are so confident of the new diesel's performance they are predicting it will attract fans of petrol as well as diesel drivers from rival manufacturers.
But Marc Raven, Citroen's public affairs director said: 'We must be realistic, however, because the Xantia 2.1 TD and now the 2.0-litre HDI is not going to be the volume model. The main seller has been the 1.9 litre turbodiesel and when the 90bhp 2.0-litre HDI is launched then we would expect it to attract petrol buyers because of the astonishing saving they can make on fuel consumption.'
However, the firm would not be drawn on exact expectations for diesel sales figures, although they should be above current levels. Fleets can expect to see the 90bhp HDI, which cuts power by taking out the intercooler used in the 110bhp HDI, appearing in the Xantia towards the middle of next year, along with the Xsara and the new Picasso people-carrier.
The new Xantia 2.0 HDI is available in SX and Exclusive trim, with equipment levels revised upwards, and also LX level, brought in to appeal specifically to fleets. An estate version is also available with the same engine and trim line-up. Prices have increased for each trim level, although equipment has also increased substantially, with side and front airbags standard for passenger and driver throughout the range.