Citroen's Scroogemobile

Is this the ultimate Scrooge when it comes to fuel usage?

Undoubtedly so. Concealed beneath the skin of this standard looking (apart from the livery) Citroen Berlingo Multispace is a cutting-edge hybrid diesel powertrain that upstages even Toyota's parsimonious Prius.

The project was a joint venture between Citroen and technology partners Ricardo and QinetiQ and it reportedly sets new standards for carbon emissions and fuel economy in a production-ready car.

How's this? Citroen claims the diesel-electric Berlingo consumes just 3.75 litres of fuel per 100km (that's over 75 miles per gallon on the old scale). To put it another way, it's a 30 per cent improvement in fuel economy and CO 2 emissions when compared to the equivalent diesel production vehicle.

Citroen says the five-door Euro IV compliant demonstrator meets all the expected performance, comfort and safety levels for today's market.

The only hurdle that prevents the technology from being offered for sale straight away is cost. However, that's likely to be overcome within the next few years, and you can expect to see diesel-electric Citroens in showrooms before the end of the decade.

How does the drivetrain function?
Here's how, in a nutshell: motive power is provided by a 1.6-litre HDi (turbodiesel engine), which is supplemented by a compact 23kW 288V DC electric motor mounted between the engine and the transmission.

Around town, the electric motor provides up to 130Nm electrical torque assist to take the load off the diesel engine. This obviously benefits fuel economy and provides lively step-off from traffic lights.

The Berlino prototype also features regenerative braking to maximize efficiency. This basically entails using energy that would otherwise be dissipated during braking to recharge the advanced 288 volt Lithium-Ion (Li-Ion) battery pack.
Drive is relayed to the front wheels via a five-speed Sensotronic automated manual transmission.

Supporting systems including a low-temperature cooling circuit to protect the electric motor and power electronics, an electro-hydraulic power assisted steering system, electrically powered air conditioning and a touch-screen driver display.