| First Drive | Munich, Germany | BMW 320 EfficientDynamics |

Late last year we drove a pre-production version of the BMW 320d EfficientDynamics saloon. Here we have the production car, which goes on sale this month (March 2010). It's not a whole lot different bar some minor statistical variations. We liked it then; we still like it now.

In the Metal

The fundamental visual difference is that the EfficientDynamics edition is not offered with the M Sport pack that the majority of 3 Series customers go for. That means standard bumpers and 16-inch aerodynamic alloy wheels are your lot.

Otherwise, it's as per the regular 320d, unless you're so into your diesel 3 Series that you can tell that this one rides 15mm lower than the 320d SE. It has low rolling resistance tyres too, contributing to a slightly lower drag coefficient, and the gear ratios are different, though you obviously can't see that...

What you get for your Money

This version of the 320d is all about the numbers. That's for you, your boss and the taxman. Compared to the standard 320d, this emits 19g/km less CO₂, boasts 10mpg better combined consumption, has 22lb.ft more torque and there's a fiver in the price difference. Impressed? So are we. Even the 0-62mph time is only 0.1 seconds slower, despite losing 13bhp. It lists at £27,280.

Those numbers, crucially, mean it's a fleet buyer's dream. It falls below the 110g/km mark, which means that for the first year the company can write off the car's entire value for tax. It only costs £35 per year in VED and its benefit-in-kind rating is 13 percent.

Driving it

The only noticeable compromise over the standard 320d from the driver's seat is a noise penalty from the engine at higher revs. What the 320d ED adds in low-rev refinement via its main driveline innovation (we'll come to that), it loses in smoothness and refinement at the top end; unlike most BMWs, this is not one that you'll particularly enjoy revving.

That said, it's hardly agricultural, and in all other respects the 320d ED is a million miles away from an 'eco' car. There's loads of torque, so it feels strong in all its six gears, and the lovely balance of the rear-drive Three's chassis remains. It's a car you can actually enjoy driving.

The usual criticisms apply: slightly harsh ride; cabin looking a little dated and monochrome these days; too many of them on the road; and not that well equipped. But look at that economy against the performance and it's difficult not to be impressed.

Worth Noting

The flywheel. They're not two words we ever thought we'd begin this section with, but the ED's innovative 'Centrifugal Pendulum Absorbers' are quite remarkable. In essence, a set of sprung weights on the flywheel smooth out the vibrations at low revs - the vibrations that make you feel you're about to stall and so cause you to change down a gear. It means the car can happily sit at very low revs without the associated driveline vibrations, so you change gear less, keeping the engine speed low, thus improving economy.

What's more, BMW hasn't ruled out putting it into other models. Makes sense really.

Summary

For the punter - you know, the person spending his own money that wants to look the part - the economy difference might not be worth foregoing the big alloys and butch M Sport kit. However, let's not belittle the achievement here. This 320d might be a little rough around the edges, but it's hardly noisy, has all the flexibility of the very flexible standard car, yet boasts genuinely supermini-rivalling economy. BMW could justifiably have charged more for it, but hasn't. Hats off for that. Plus you'll annoy the taxman. Win-win.