Road Test: BMW 3 Series 320d BluePerformance EfficientDynamics 4dr

Whether you see ‘eco' as ecology or economics, BMW has done a lot to help us associate those three little letters with everyday cars. We're used to the basics now: less friction in the engine and at the road surface, more slithery aero, longer gearing to maximise fuel economy and emissions, etc. But, rather than being an unsexy option, a last-minute penstroke under the watchful eye of a company-car boss, it should now be an automatic - and genuinely satisfying - choice. And what the engineers started with the first 320d EfficientDynamics has become a well-developed science with this latest one.

As you'll have noticed, the tech now comes as part of the all-new 3-Series, so it's lighter, roomier and even better to drive. Like before, the 2.0-litre diesel is a regular 320d engine turned down a bit, with 161bhp and CO2 emissions of 109g/km. That qualifies it for all sorts of tax breaks that'll save your accountant days of fiddling. Importantly, it costs the same as a 320d SE, and now comes with an optional eight-speed auto that - rather smartly - doesn't bump up the emissions.

Other new bits include an Eco Pro mode that softens the throttle, minimises power-suckers like heated seats and gives you prompts to edge closer to the claimed 68.9mpg average economy. But should you choose to ignore all that, just pop it into Sport mode, and it'll behave like a... BMW. Top speed is 143mph, and it takes care of 0-62mph in eight seconds, without ever feeling hesitant or juddery at creeping speeds, like some eco cars often can (thank a centrifugal pendulum in the clutch movement for that, apparently).

A quick look around the opposition shows that, although the equivalent C-Class or even Insignia come close-ish, they can't match the ED for CO2 and fuel economy, nor speed and power. It's also the most pleasing to take down a decent road. BMW reckons a fifth of all 3-Series sold in Britain will be EDs. We're surprised it's not more.