Forget everything you ever heard. Diesel isn't dull

 

ROAD TEST/BMW 32rd: There are good diesels around, but the new 320d from BMW shows just how good they can be. Andrew Hamilton is behind the wheel

We keep enthusing about diesel but it's really difficult to stay away from the subject. Diesels used to be so agricultural and now they're powering not just mainstream models with prestige badges but sports coupes as well. Who could have believed it?

Equally incredulous is the fact that we are now recommending a BMW diesel over its direct petrol equivalent. That's how it stands with the brilliant new 320d. Reworked late last year, and with a fresh new face, a high-tech four-cylinder diesel engine and a raft of chassis improvements, it makes the equally new 318i look a tad disappointing in the overall scheme of things.

It comes into Irish BMW showrooms at €38,750 ex works or over €2,000 more than the 318i, which is €36,300 ex works. This super-efficient car gives an alluring mix of sporty performance and exceptional economy that has to be hard to resist, even for the most committed petrol drivers. First though, the reworked 320d stands out because of fresher styling. Up front there's a wider kidney grille, curvy new headlamp assemblies and a deeper bumper. The bonnet is now more heavily contoured and at the rear, there are new jewel-effect tail lamps.

Under the bonnet is BMW's new 2.0 litre four-cylinder direct-injection diesel. This four-valve-per-cylinder engine has been developed new from the ground up. Key among its innovations is a second-generation common-rail injection system from Bosch. In combination with a new digital engine management system, it provides the engine with far greater efficiency and refinement than before. Complementing the delightful running behaviour is a turbocharger and intercooler that helps smooth out the power curve and reduce lag.

The 2.0 litre unit develops 148bhp at 4,000rpm. Like most diesels these days, the emphasis is much more on torque for mid-range pulling power. On the road, the 320d feels every bit as rapid as its performance credentials suggest. The official 0 to 62mph or 100kph figure is 8.9 seconds, which is an improvement on its predecessor by a whole one second. It also betters the time of the 318i, despite being burdened with an extra 95kg in kerb weight.

Where the 320d really wins out, however, is during overtaking. With so much torque concentrated low down and a slick-shifting five-speed manual gearbox to exploit it, in-gear acceleration is superb. BMW claims a fourth gear 50 to 75mph time of just 7.5 seconds. That's a full 1.7 seconds faster than the 318i.

Diesels are that bit noisier, that bit more vibrating. With the 320d, there are twin balancer shafts to quell nasty vibrations so that the diesel unit remains commendably quiet and composed at motorway speeds. It's only when the driver floors the throttle and winds the revs to around the 4,700rpm cut-off point that the traditional diesel clatter becomes conspicuous.

Of course, the peppy performance and improvement refinement is really only half the story with this talented car. An even bigger asset is its economy. BMW claims a combined figure of 55mpg - an impressive 6mpg improvement over the old model, to give a theoretical range of over 700 miles on the 63 litre tank. By comparison, the 318i is said to return 39mpg. On our Irish test which was a mixture of town driving and up-hill and down-dale country work, we achieved an overall 46mpg with the 320d, a highly creditable result. Its frugality begs one question. In these days of high fuel prices, can there be better justification for switching to diesel?

It's environmentally good too, with a comparatively low 148g/km CO2 emission rating. Because of company car taxation, that's very important in the UK just now. There, the 320d is expected to account for up to 20 per cent of all 3-series sales.

Elsewhere the 320d puts on a commendable show. The added weight of the engine in the nose fails to dull the handling to any great degree. The chassis is beautifully balanced, and with recent changes that BMW has made to the steering, it feels a good deal sharper than the old 320d, delivering crisp responses and tremendous agility. Most of us would have a long way to go before finding a diesel car with such outstanding dynamic behaviour. It also rides with great maturity, absorbing ripples and ruts calmly and silently.

OVERALL, the 320d is an exceptionally well-rounded car: we got to appreciate it more the further we drove it. The interior is a study in clarity and quality, while the quality itself and the standard safety features are among the best in class. There are other good diesels, some with smart badges, but we think the 320d is probably the shining example of how far diesel motoring has progressed.