BY 2020, all car manufacturers will have to achieve an average C02 emissions figure of 95g/km, averaged out across their entire product range, so we are now seeing an increasing number of low emission vehicles.

Different manufacturers are approaching this goal in different ways, but all are actively seeking ways of reducing emissions, some are introducing highly economical low C02 engines, others are introducing hybrid and all electric cars  and many, like Citroen, are doing all of the above.

The latest step in this development process for Citroen is a new three-cylinder engine family called PureTech, which will help the French car maker reduce its overall C02 emissions from its current average in 2012 of 123g/km.

Earlier this year, in another step towards its long-term goal, Citroen followed Peugeot's lead and introduced a diesel hybrid version of its distinctively designed DS5 - the PSA group being the only manufacturer so far to marry electric motors with diesel technology.

Citroen will also unveil an all-electric version of its Berlingo model at next month's Brussels Motor Show.

The all-new three-cylinder PureTech engines are produced with 1.0 and 1.2-litre capacities, with 68 or 82bhp respectively, although only the larger of the two engines is available to UK customers.

The C3 VTR+ 1.2 82bhp manual costs £13,640 on the road and is on sale now. In the DS3 range, the new VTi 82 engine is available in the DSign model with a manual gearbox and costs £12,850 on the road.

The new engines are designed to deliver excellent fuel economy - up to 65.7mpg - and low C02 figures of 99 and 107g/km respectively.

These engines, more compact and lighter in weight, produce less C02 than their four-cylinder predecessors and are more fuel efficient.

Producing 68bhp per litre, the 1.0 unit has twin overhead cams with four valves per cylinder and features variable timing to improve fuel consumption and refinement.

Petrol powered versions of the C3 model account for 43% of sales around the world and around 40% in Europe.

The 1.0-litre PureTech engine with 68bhp creates 95Nm torque, promises 25-27% better economy than its predecessor and is 2.3 seconds quicker from 0-62mph, yet still only produces 99g/km C02, which is 38g/km less than the engine it replaces.

The VTi 82 comes in 1.2-litre guise, but still with three cylinders. It produces 118Nm torque, but with a slightly higher C02 emissions figure of 107g/km, 35g/km less than its predecessor, with a 0-62mph time of 12.3 seconds.

During the launch on the outskirts of Paris, we drove the 1.2-litre version of the new C3 model on a relatively short and unsurprisingly busy test route which included a mix of town, A-road and motorway driving.

Three-cylinder engines are never going to set the world on fire in performance terms, but the car is quick off the mark in traffic and cruises perfectly quietly at motorway speeds, with in-gear acceleration best being described as "progressive", but use the gears, and there is enough power there to make good progress.

If you work it hard and rev it towards the top end of its range, the endearingly distinctive three-cylinder note increases to quite raucous proportions.

The suspension and steering have also received attention, adding a firmer feel and more dynamism to the driving experience.

I thought the ride quality was good - it cushioned most of the bumps, yet retained responses from the steering which weighted up nicely through the bendy bits.

Another noteworthy development comes in the attractive and popular DS4 model line, with 160bhp HDi  versions now getting the option of a new 6-speed automatic gearbox.

Citroen has sold 55,000 DS4s so far, with a high proportion of those sales being high spec models, with 80% of customers opting for the leather and fabric upholstery, so the addition of this smooth-shifting auto will add to the DS4's appeal.

Citroen expects this particular model, with its 160bhp HDi engine and auto gearbox to represent around 40% of DS4 sales.

The new auto box is now available on two DS4 models, the DStyle costing £23,545 and the DSport £24,545.

The model we drove was the top-spec DSport version, with a smart leather trimmed dash and the optional 19in alloy wheels, which looked very smart, but did compromise the ride quality on broken road surfaces, so if you prefer function over fashion, I would suggest sticking to the smaller, standard rims.

The stylish DS Line has proved a winner for Citroen, with 270,000 examples of the DS3, 4 and 5 having been sold to date.

The company is also expanding its global reach, having recently launched the DS3 in China, the DS4 in Argentina and the DS5 in Brazil.

Currently, Citroen sells 33% of its total volume outside of Europe, but in the next few years, as sales grow in new markets around the world, the company expects this figure to grow to 50%.

There are a lot more exciting developments on their way from Citroen, starting next year (2013) when the Cabriolet version of the DS3 makes its debut before going on sale in the Spring - just in time for the summer.