SUCH has been the pace of progress in a few short years that we’ve come a long way from the novelty of cars with low CO2 ratings.

Even engine stop-start systems are steadily becoming the norm - we often expect them to be standard now.

No company can take more credit for exposing the motoring public to such things more than BMW. Through the German firm’s Efficient Dynamics programme, numerous cars within its range boast class-leading levels of CO2 and economy figures. And nowhere more than in the company car sector has such progress been so welcome.

Just when rival manufacturers think they’ve gotten close to BMW it moves the goalposts again, though. Digging deeper to further reduce emissions and fuel consumption, it’s the end user with growing tax bill that benefits.

Nowhere is this more obvious than with BMW’s new 3 Series model, the 320d Efficient Dynamics variant. It might sound ungainly, but BMW has thrown the high-tech kitchen sink at its key, fleet-friendly model in a bid to get the numbers to new highs - and lows.

Although BMW’s range has grown in recent years, the 3 Series remains a cornerstone of the firm’s popular line-up. This is most obvious in the compact premium fleet sector, and when you’re paying serious sums in tax you want your car to keep most of your hard earned money in your wallet.

So important is the company car market to BMW in the UK that it lobbied hard for its German bosses to agree to a super-efficient 3 Series to maintain its already strong position in the market.

And what a car it got. At the end of the day it’s a numbers game in the fleet sector, and the numbers are stunning. Boasting a CO2 figure better than most superminis - 109g/km - plus and equally impressive combined economy figure of 68mpg, only the taxman is likely to be disappointed.

This is no real-world compromise, though. At this car’s heart is a 163 horsepower, four-cylinder diesel motor capable of outputting a healthy 280lb/ft of torque, helping to send the car on its way to 62mph in a very un-green eight seconds.

As a showcase for what’s possible - and affordable - this particular 3 Series nails it. The kitchen sink approach to the underlying technology works as you’d expect. We’re all used to seeing various Efficient Dynamics elements on an increasing number of BMW models, and this 320d has it all.

From an engine tuned to run cleaner and greener and the inclusion of an ignition stop-start system to low rolling resistance tyres, subtle aerodynamic improvements, a gear shift indicator and modified gear ratios, all these individual features combine to deliver that magic 109g/km CO2 figure and, for the accountants in the room, road tax on a par with a one-point-nothing city car.

On the road this car drives like any other 160-odd horsepower 3 Series. This is good news, as the last thing you want is to have to modify your driving style to achieve the sky-high mpg figure. Being realistic, it’s likely that the car will be driven sensibly by the fleet community, making it a relatively easy job to keep the fleet manager happy and the expense account solvent. There’s no bone-hard ride and engine and road noise has been kept to a pleasing minimum - pretty much as you’d expect from any 3 Series BMW.

As an example of what can be done to reduce emissions and fuel consumption, this 3 Series is an impressive achievement. That is has been done without any hint of a compromise regarding the driving and ownership experience shows that making savings doesn’t have to hurt.

And remember, this is a compact executive saloon we’re talking about here, not some city car with only enough room for a briefcase in the boot. If you think this is impressive, just think what’s possible with the rest of its range. As it stands, this 3 Series is something of a game-changer.

FACTS AT A GLANCE

Model: BMW 3 Series 320d Efficient Dynamics, from £27,245 on the road
Engine: 2.0-litre turbo diesel unit developing 163bhp
Transmission: 6-speed manual transmission as standard, driving the rear wheels
Performance: Maximum speed 142mph, 0-62mph 8.0 seconds
Economy: 68.9mpg
CO2 Rating: 109g/km