BY PHILIP LORD | 24th Nov 2009
This car accelerates on the broad shoulders of its torque curve, and while it doesn’t have maximum torque from zero revs like an electric motor, it is not far off it.
Without the turbo lag of most diesels, it launches off the line with a whack of torque while the traction control light flickers madly on the dash as it works hard to quell wheelspin.
Between about 1500rpm and 3500rpm, the scenery flies past as if you have hit the fast-forward button on your DVD player.
Those used to petrol engines are tempted to use a lower gear on entering a corner. No need. Instead, the corner can be exited from about 2500rpm.
It is hard to shoebox this new generation of BMW high-performance diesel it certainly does not fit the diesel stereotype.
It almost has the power and torque characteristics of the mid-1970s large displacement Aussie V8s – which never liked being revved over 5000rpm, and were all about torque, really – except that the 330d is faster, smoother, quieter and much, much more economical. Such is progress.
The engine is quiet and smooth and emits an enticing, guttural bellow as the tacho flicks through its abbreviated sweep.
But it is not all cream with this engine – a tinge of engine vibration filters through the steering wheel as the engine settles into a 1600rpm cruise in sixth gear at 100km/h.
Although the engine may let you know it is a diesel from time to time, the nicest reminder comes at refuelling time. Despite being given a hiding on twisting back roads the fuel consumption peaked at 8.9L/100km on test. We achieved 6.8L/100km with easy freeway running and an average of 7.6L/100km for an urban/interurban mix.
The six-speed transmission is smooth in gentle driving, but in traffic, it can be too keen to select a higher gear and then thump on kick-down when the throttle is squeezed for a burst of acceleration.
The massive torque produce by the engine from low revs presents its own problems at low speed on bumpy roads too, where it’s hard to modulate the throttle when even a slight squeeze delivers a massive wedge of torque.
Bumpy roads around town might highlight the sensitive throttle but it’s not just the throttle to blame. The 3 Series does not have the ride quality of its nearest competitors, with what feels like the job of suspension compliance being devoted too much to the tyre sidewalls.
Although the springs and dampers do a fine job over bigger bumps, the 330d sometimes falters and bounces over sharper bumps such as uneven road joins, corrugations and potholes.
The steering is unusually heavy around town but delivers excellent feel as speeds rise – surprisingly for electric power assist – and allows superb precision through corners.
The chassis is responsive and agile – provided that the road is not chopped up too much. Usual practice is to build diesel engines with a heavy iron block but the 330d’s is one of an increasing number of lightweight alloy-block diesels. It helps weight distribution and the 330d certainly doesn’t feel nose-heavy.
The 3 Series interior is, as always, an inviting and cosy place to be, and with the current trend for cab-forward designs, the E90 3-Series is unusual in that you feel as if you’re sitting close to the head rail and A-pillar when in the driver’s seat.
The control placement is clear and logical and the cabin feels beautifully crafted. The much-maligned i-Drive multifunction controller in this updated iteration is a far more logical and easier to use than when it first appeared in the 7 Series.
While the interior design is uncluttered, it is missing the extra bins and cup holders that owners find useful and that are increasingly offered elsewhere. Slim door pockets, fold out dash cup holders (which are on the small side) and a fairly useful centre bin is about it, along with small door pockets in the rear.
The front seats are not as enveloping as some might like for fast cornering but are still comfortable. Most occupants will find a comfortable setting with the electric adjustments up front.
The rear seat is not so accommodating, with a lack of knee room, and while the outboard passengers have a relatively comfortable seat, the centre seat is not really one you want to sit in often, with a firm backrest against the spine and a high transmission tunnel to tangle the legs.
The boot is quite small but it has a large underfloor bin. Rear seats fold down for longer items.
The 330d offers an impressive mix of agility, performance and economy, and even though the cabin seems a bit tight on space and the ride is not brilliant, the 330d still makes a persuasive argument given its relatively small premium over its four-cylinder sibling, the 320d.