Review of the new BMW 318d

If the BMW 318d were a pop star, it'd be Jim from The Corrs; the one you don't tend to look at in an otherwise glamorous line up. The M3 and the more powerful diesel models may make car journalists hearts go pitter-patter and attract the flowery prose but the plain Jane 318d might just be the smartest buy in the whole 3 Series line up.

Costing from £24,100 and priced around £1,100 less, model for model, than the larger-engined 320d, the smaller of the two four-cylinder diesel engines is still capable of putting on quite a show. Although there's very little in it when it comes to fuel economy or emissions, the 318d scores a decisive advantage over the 320d when it comes to insurance costs, being rated a couple of groups lower at Group 12. There's not too much in it as regards fuel economy, both cars managing around 60mpg, while the spec sheet says that the 318d will emit just 123 grammes of carbon dioxide per kilometre, putting it on par with some tiny superminis. The bad news is that it won't save company car buyers much more than the 320d.

The 318d's outstanding economy and emissions figures come courtesy of BMW's EfficientDynamics technology. While other manufacturers were messing about with hybrids and biofuels in their attempts to go green, BMW developed a programme that enhances a vehicle's efficiency through a series of small measures that have a big combined effect. Features including Auto Start-Stop, Brake Energy Regeneration, high precision direct injection, active aero dynamics and optimum gear shift indicators go into EfficentDynamics and the results put BMW products near the top of the tree when it comes to environmental considerations.

"The 318d offers a relatively cost effective first step on the diesel 3 Series ladder"

So why should you pocket the grand over the 320d and suffer lower performance and a less elevated image? It's a valid question. The issue is thrown into a different light when you consider that these two cars have much the same engine, with a few electronic tweaks on the ECU being the most effective difference between their respective power outputs. Some customers may be tempted to opt for the 318d and pay £350 at an aftermarket tuner like Superchips to have their motor boosted to generate more power than the 320d. You'd need to have a close look at your warranty small print, not to mention the effect it would have on your insurance premium but it's certainly a way of circumventing this rather contrived model differentiation on BMW's part.

In case you're wondering, the software jiggery pokery limits the junior model to 143bhp and credits the 320d with the full 177bhp monty. The upshot of this is that the 318d will feel a little sluggish if you drive it back to back with the 320d, but otherwise it's an agreeably swift compact executive model, notching off the dash to 60mph in 9.3 seconds and running on to a top speed of 130mph. The excellent six-speed automatic gearbox offered as an option on the 320d sadly isn't available to 318d buyers. If you are dead set on this automatic, this could be the real deal breaker but otherwise although the heart may say 320d, the head more often than not opts for the 318d. The six-speed manual gearbox fitted to this Three is one of the best in the business, slick, oily, positive and wristy. Coupled with excellent pedal positioning, you'll be changing gear just for the fun of it.

One of the eternal trademarks of the 3 Series is rear wheel drive and although the 318d doesn't possess tyre-scorching power to capitalise fully, I've still noticed the benefits. Deploying the full quota of 300Nm of torque as you accelerate out of a side turning would, in a front-wheel drive car, generate copious torque steer, that raggedy tugging of the steering wheel as the front tyres struggle to put down the power. Even at higher speeds, front-wheel drive cars with a hefty slug of torque can veer rather dramatically when they come 'on-cam'. There's none of this corrupting influence with the 318d. About the most extreme thing that ever happens is that in damp conditions the ESP light will give a little blink as it winds the power back slightly. Most of the time it just grips and goes with no drama, no writhing steering wheel or tramping axle. It's a masterclass in chassis engineering.

The E90 generation Three has been with us a while now and buyers are starting to get used to it. Developing an all-new 3-Series was never going to be easy and the latest car shows that the money men and the stylists have gone head to head in the battle between shifting big numbers and continuing the trend for challengingly styled BMWs. It looks like the stylists have blinked first, the 3-Series looking a good deal more conservatively penned than the rest of the BMW line up. Although those wearing the black polo necks may grumble, it's a wise choice. With the 3-Series accounting for fully 52 per cent of BMW's UK sales, alienating this bedrock of customers with a wilfully odd looking car was never going to make a sound business case. Although sales of the latest 5-Series have swelled as people became used to its sharky lines, for the first few months that styling was manna from heaven for Mercedes and Audi.

Many of the contemporary BMW styling signatures are present, although they have been toned down radically. The sill line is bowed, although nowhere near as radically as in, say, a 1-series. Compare how the rear bootlid is a chamfered and smoothed version of that worn by the 5-Series. Even the flanks betray a less aggressive concave contouring, while the rest of the traditional BMW cues such as the 'Hofmeister Kink' at the rear window and the kidney grille are present and correct. Although it's not what you'd call a striking piece of design, it is nevertheless mature, assured and classy.

The 3-Series also has to redefine its place in BMW's range. For the first time in 29 years, it's no longer the entry level BMW model, and the range must be planned so that 1-Series buyers can easily migrate to a Three on the way to bigger BMWs. At least that's what the suits in Munich are hoping. The 318d is a key part of this stepping stone philosophy.