BY JAMES STANFORD | 24th Nov 2009
BMW Australia was late to the diesel party, not offering a diesel here until 2003, but is catching up and claims to have more diesels than any luxury brand here.
Just a few weeks ago, the company introduced a 7 Series with a potent 3.0-litre diesel engine under the bonnet. Now, it has introduced its second diesel 3 Series, which runs the same diesel engine.
When you consider the 7 Series diesel (730d) is no slouch and that the 330d is 315kg lighter, it makes a rather compelling case.
If you are considering buying a naturally-aspirated petrol 325i for $75,900, just take a 320d for a drive before signing on the dotted line. Chances are you will opt to scratch together a few more pennies ($11,350) and go for the potent diesel.
While BMW’s petrol engines have always been a treat at the top of the rev range - 6500rpm and above - this diesel is so strong that it has the power to convert many a diesel sceptic.
Of course, the diesel can produce all of its torque from 1750rpm, but it is still fun to rev out. We experienced this first hand on a twisty mountain run near Mt Beauty in Northern Victoria this week at the 330d launch. Because the engine revs smoothly you end up winding it out to 4000rpm.
It doesn’t scream like a petrol engine or sound half as good, but this diesel is almost as engaging. The engine does have a fairly sporty engine note and doesn’t really sound like a diesel, but then again it doesn’t give off the wonderful note that a naturally-aspirated straight six when pushed hard.
BMW engineers have done a lot of work to suppress the diesel din and if you listen closely you can tell it's not a petrol engine at idle, but it really does not stand out as a diesel and certainly does not clatter like older or cheaper diesels.
Just as is the case with the twin-turbo petrol six 335i, you have to go a bit easy on the throttle to avoid intervention from the traction control system. If you're feeling brave you can turn the traction control as well as the stability control.
The traction control gets a good workout if you leave it on, as you could well imagine with 520Nm of twist that can be unleashed suddenly when the turbo spins up quickly.
The pulling power off the engine is addictive. Come out of a corner, drop your right foot and it will sling forward with the kind of acceleration that makes driving fun. We bet a lot of passengers will be surprised by the performance and then shocked when the driver informs them it is a diesel.
The six-speed automatic is quite a good transmission, aided by so much engine torque that it doesn’t have to hunt around for the right gear. And the shifts are smooth.
Until recently, it would have been one of the best around for keen, sporty driving, but these days you can’t help but wonder how much better this performance diesel would be with a dual-clutch automatic, as fitted in the M3 and 335i coupes and many Audis.
As it is you have to wait a moment for the transmission to change gears, even when you are shifting automatically - via the paddles on the steering wheel or the gearshifter on the console. It's not a long wait, but it is a moment longer than a dual-clutch auto.
When you're running along an exciting mountain pass, the last thing you're thinking about is economy, and we certainly pushed the engine like we weren’t paying for the fuel. At halfway mark of our drive I checked the fuel consumption and was surprised to see the average consumption for the day sat at 8.2 litres per 100km - that's remarkable given the flogging it was given on one of the legs.
Yes, some easy highway cruising helped keep the figure down, but it was still far lower than achievable by any petrol engine offering similar performance. More highway time on the return trip saw the economy drop back to 7.5L/100km, which is again good for a mid-size luxury sedan.
Of course, there are likely to be many people who opt for the 320d over a petrol equivalent not due to any economy argument, but for the overall performance and the ability to call on all that pulling power without having to work the engine hard at all.
So what about handling?
Diesels traditionally are heavier at the front-end and encourage a car’s nose to push on in bends. That is why BMW has spent so much effort making this diesel as light as possible, including by going to the trouble of an alloy block.
It has all worked a treat because the 330d is as lithe as any other sporty BMW. There is the meaty and direct steering which gives you a good idea of where you are headed in corners and minimal bodyroll, which make changing direction something to look forward to.
The only problem is the ride. Just like they do when it comes to how well they want their steak cooked, people have different opinions on how firm a car’s ride should be. But it is as clear as bottled water that the 330d is too firm.
Is it the run-flat tyres that take away a tyre’s ability to absorb some of the shock of potholes and bumps because the sidewall is so thick? Is it that the spring and damper rates are tuned for a bowling alley-smooth autobahn and not Australian country roads?
I’m not a chassis engineer so I really don’t know, but something is not right down there. The set-up is so firm that the wheels actually seem to struggle to keep contact with the road in bumpy corners when pressed hard.
The chassis crashing comes through the body and you can even feel it through the steering wheel, though not in the form of traditional steering rack rattle.
On open sections where the road is not quite highway-smooth, the suspension picks up every imperfection.
Some people expect sporty cars to be firm, but having spent time recently in a Nissan 370Z which is a more overtly sporty car I would have to say the Nissan is more comfortable on rough roads than this BMW. Of course it is extremely comfortable on smooth surfaces, but the most enjoyable roads in Australia have their fair share of lumps and bumps, which become a chore in the 330d.
The interior of the 3 Series we drove featured light cream coloured leather called Oyster (a no-cost option) which combined with the black surfaces looked modern and stylish. The standard seats are comfortable and have quite substantial side bolsters that keep you centred when whizzing around those corners.
Our car also had the optional premium satellite-navigation, which costs a bundle ($4100). It is interesting that car-makers continue to charge so much for these systems when they are available for a fraction of the price in plug-in units, watches and mobile phones.
That said, the premium BMW system is quick, has excellent resolution and has a very impressive 3D feature which shows the gradient of where you are headed.
It's not of all that much value though, because you can usually see the hills in front of you, but it does look good.
Metallic paint is also still an option, and not a cheap one, either, at $1840.
There is sufficient room in the rear for two adults with ample headroom and just enough legroom, and a big boot.
The 330d is a practical prestige sedan that has excellent performance and is also economical, so if you don’t mind the harsh ride, the 3 Series super-diesel ticks just about all the boxes.