First look: Twin-turbo diesel for C5

AUSTRALIA’S diesel craze continues to snowball, with confirmation Citroen’s popular C5 HDi sedan and wagon range will swell to include three turbo-diesel options in 2007.

Revealed this week by Citroen is an all-new 2.2-litre twin-turbocharged oil-burner that produces 125kW of power and 370Nm of torque from just 1500rpm. It will be available in Australian C5s by early next year, positioned above the C5 HDi’s existing 100kW/340Nm 2.0-litre turbo-diesel.

The latter will be paired as standard with a new Aisin-sourced six-speed automatic transmission from August, in both sedan and wagon guises. As announced last week, the upgraded six-speed C5 (2.0-litre) HDi will be priced at $49,990.

Not content with just two oil-burning C5 variants, Citroen says an even more powerful V6 turbo-diesel will also join its HDi large car line-up, which already accounts for 80 per cent of C5 sales in Australia.

While the local Citroen distributor, Ateco Automotive, remains coy about exactly when the 2.7-litre twin-turbo V6 will power Australian C5s, the same engine debuted Down Under last year in Peugeot’s new 407 Coupe HDi, which is priced at $72,500 and delivers 150kW at 4000rpm and 440Nm of torque from 1900rpm.

The jointly-developed Ford/PAG-Peugeot/Citroen V6 turbo-diesel was also released last month in Jaguar’s first diesel model, the S-Type 2.7D, which produces 153kW and 435Nm, and is priced at $101,490.

A single-turbo version, offering 140kW and 445Nm also powers Land Rover’s Discovery and Range Rover Sport models, priced from $66,250 and $85,000 respectively.

Peugeot Automobiles Australia is expected to offer both the new 2.2-litre four-cylinder and 2.7-litre V6 turbo-diesel engines in its 406 sedan and wagon range from around October.

In the meantime, Citroen has claimed big performance and economy gains for the new 2.2-litre oil-burner over the 2.0-litre four it will be sold alongside.

Fitted with a particulate filter as standard, the latest C5 HDi engine features a parallel sequential dual turbo, which is claimed to be a world-first for a four-cylinder diesel engine and aims to boost engine response at low speeds.

Each of the two identically-sized, fixed-geometry turbos supplies around half the air input required at high engine speeds. Below 2700rpm only one (low-inertia) turbocharger is operational, and is claimed to deliver instant engine response as well as up to 40 per cent more torque than the existing engine. Beyond 2700rpm, both turbochargers operate.

Combined with a new Extreme Conventional Combustion System (CCS) equipped combustion chamber and a third-generation common-rail fuel system with increased (1800-bar) fuel pressure, it’s claimed to reduce emissions while improving performance.

Citroen says the new 2.2 C5 HDi accelerates from 30 to 60km/h in third gear in 3.6 seconds – 20 per cent quicker than the 2.0 C5 HDi.

The new 2.2-litre HDi engine is also 40mm shorter than its 2.0-litre predecessor, allowing the removal of "hard spots" in the C5’s bonnet, which Citroen says also makes the upgraded model more pedestrian-friendly.