The Citroen C5 inaugurates the new micro-hybrid technology that will be widely applied to numerous models in the range. Initially it will be available with the HDi 110 DPFS version equipped with the EGS6 electronic gearbox system with steering-wheel paddles and low rolling resistance tyres.

The micro-hybrid technology consists of a second-generation Stop & Start system, which retains an alternator-starter, or reversible alternator, boasting enhanced performance. Power has been increased on the first-generation system, by 70% to 2.2 kW, and now includes a power electronics unit. Fitting the system on a diesel engine constitutes a world first for a passenger car.

Start-ups take just 400 ms, half the time of a starter, and remain completely transparent for users. Noise is eliminated through the use of a timing belt rather than the gears of a conventional starter. Vibrations have been eliminated - at start-up and cut-out - by using a twin-mass engine flywheel and a sealed air regulator and by attaining slowdown speed faster.

An onboard network assistance system, called e-booster, boosts the electricity supply of the alternator using super-output, temporarily adding to the power of the battery. This set-up has several advantages, namely:

an increase in transmitted energy, improving start-up capacity for temperatures of as low as -5°C;
onboard network support via complete transparency on the energy required by the alternator, to maintain the performance of the lights, windscreen wipers and radio;
a function that optimises battery charge and super-output through energy recovery when drivers take their foot off the pedal or slow down, with a slight increase in the engine brake.

The Citroen C5 e-HDi is also equipped with an optimised watertight battery sized for up to 600,000 restart cycles. Engine suspension has been enhanced on the Citroen C5 for increased comfort during stops and re-starts.

The new equipment considerably reduces the Citroen C5's fuel consumption and CO2 emissions. Over a combined cycle, the diesel model consumes 4.6 l/100 km and emits 120 g/km of CO2. In an urban cycle, fuel consumption and CO2 emissions are up to 15% lower.