BMW 123d Convertible 2010 Review

Price Guide (recommended price before statutory and delivery charges): $69,480
Options fitted to test car (not included in above price): Nil
Crash rating: N/A (see text)
Fuel: Diesel
Claimed fuel economy (L/100km): 5.7
CO2 emissions (g/km): 150
Also consider: Audi A3 Cabriolet, Volkswagen Eos, Peugeot 308CC, MINI Cabriolet, Renault Megane CC, Volvo C70

Overall rating: 3.0/5.0
Engine/Drivetrain/Chassis: 4.0/5.0
Price, Packaging and Practicality: 2.5/5.0
Safety: 3.5/5.0
Behind the wheel: 4.0/5.0
X-factor: 4.0/5.0

BMW's 1 Series is proving to be a fruitful platform for the company. Currently, it spans from five-door hatchback range to the upmarket 1 Series convertible. The latter is described as the company's "first compact luxury convertible for more than 30 years."

This being so, the 1 Series soft-top convertible's antecedent must be the E21 3 Series based Baur cabriolet -- a company-sanctioned conversion of the regular 3 Series two-door with a convertible targa roof that was first seen in Germany in 1978. The E21 323i Baur cabrio came to Australia in 1982 and was succeeded a year later by BMW's own E30 convertible.

BMW's small convertible diverted from its "compact" origins as the 3 Series grew progressively in size and expense. Today's 3 Series hardtop coupe-convertible is a long way from the Baur original.

In BMW's thinking, the growth of the 3 Series, in both size and status, left a nice little niche for a new, small ragtop. Thus the 1 Series convertible was developed -- alongside a coupe version -- to bring a worthwhile broadening of the BMW range.

Australia got the 1 Series convertible in mid 2008 and, with a pre on-roads entry price under $70,000, it returned some accessibility to wind in the hair BMW motoring (the entry-level 3 Series 325i convertible hovers just below $100,000; the two-seat Z4 sportster starts at a bit more than $86,000).

Not only that, it also brought rear-wheel drive handling into a segment where front-drive is the general order of the day, as well as a range of engines beginning with a thrifty 2.0-litre four-cylinder and ending with a high-winding, 225kW twin-turbo 3.0-litre six.

Not long after the initial launch, the range was extended with the addition of two four-cylinder diesels: the ultra-green, 105kW/300Nm 118d and the chunks-of-torque, 150kW/400Nm 123d. Somewhat surprisingly, and even unconventionally, the diesel engines share the same 2.0-litre capacity, as well as (undersquare) bore-stroke dimensions with the 115kW/200kW 120i petrol engine.

And even though the 118d is a paragon of virtue with low emissions (129g/km for the manual) and high fuel economy (4.9L/100km), the much more powerful 123d is not too shabby either. CO2 emissions and fuel economy for the manual version are quoted respectively at 140g/km and 5.3L/100km, while the auto manages 150g/km and 5.7L/100km.

The 123d convertible is quick, too: The manual gets to 100km/h in 7.5 seconds while the auto is barely any slower at 7.6 seconds.

Importantly for a convertible, the looks -- apart from a slight narrow-gutted suggestion -- are appropriately arresting. The soft-top is arguably better proportioned than the coupe with its clear definition of the upper and lower body sections. Roof-down, the 1 Series convertible is not exactly squat but it does de-emphasise the vertical in a quite pleasing way.

And, maybe strangely, the decision to go with a soft-top roof actually proves to have its positive side. There is still room for fabric in this era of full metal jackets.

Accommodation inside the 1 Series convertible is as you'd expect. Sure, it has a rear seat but, even more than the hatchback 1 Series, it is not a car to be taken  seriously for four adults. The boot, likewise, is relatively small with a maximum 305 litres (and a roof-down minimum of 260 litres), but the soft-top at least takes up less space than we are becoming accustomed to in coupe-convertibles -- and there is a ski port to allow load-through of lengthy items.

The front of the 1 Series convertible passenger compartment is a fine place to be. The cockpit isn't exactly the widest in its category, but there's no compromising of legroom, or headroom, and the front seats are supremely cosseting with power adjustment for side cushion width. In the 123d they are heated as well, although backrest and height adjustment, as well as reach, are manual operations.

It's also worth noting that the seats in the 1 Series convertible get the same SunReflective technology as other BMW convertibles further up the ladder. This means the leather runs at a lower surface temperature than normal seat leather even when directly exposed in the hot sun.

Other than that, there's precious little difference between 1 Series convertible and hatch. Dash, steering wheel, centre console are essentially the same, as is the dearth of handy spaces for regular paraphernalia such as handbags, wallets and mobile phones. And the spaces that are there -- door pockets, glovebox, centre console bin -- are quite tiny.

Standard gear includes most of what you'd expect in a premium product, so there's no shortage of flash and dash. Climate control, rain-sensor wipers, auto-dim rearview mirror, push-button start, trip computer, cruise control, rear parking sensors and a decent audio with USB port are all part of the deal.

On top of dual front airbags and front side bags that look after the head and thorax area, there are pop-up roll bars behind the rear seats forming part of what BMW calls its "rollover safety system." This includes specially reinforced front windscreen A-pillars as well as additional structural measures resulting in what is claimed to be one of the most rigid four-passenger convertibles. Also part of the BMW convertible's paraphernalia is a run-flat indicator reminding you that the convertible has no spare wheel.

The 1 Series convertible has not yet been ANCAP tested and, while the five-door hatch version gets a full five-star rating, the soft-top may just fall slightly short despite its heavy accent on passive and active safety (ANCAP star ratings for competitors range from four for MINI cabriolet and Audi A3 convertible, to 4.5 for the Peugeot 308CC and five for the Renault Megane CC).

On the road, like the 3 Series convertible, the 1 Series soft-top has a sense of presence quite different to its more workmanlike siblings. As mentioned earlier, the addition of a short, chunky boot and a fabric roof transforms the 1 Series into something probably most accurately described as cute. It's a sort of halfway house between the MINI cabrio and the 3 Series convertible.

The 150kW diesel sounds like any other diesel when fired up from cold but on the move disappears into the background to the point that at cruising speeds you'd never pick it. The response is outstanding, and what else would you expect with such power and torque figures. At a touch over 1.5 tonnes, the weight is about on par with the Volkswagen Eos, and quite a bit lighter (about 150kg) than the Peugeot 308CC.

The torque is spread over a narrower rpm band than the 118d, but plenty of the 123d's 400 Newtons are available early in the rev range. And, for a diesel, it spins out with some willingness to a higher than normal 4700rpm redline. The fact that the 150kW maximum comes in at 4400rpm indicates it's still working eagerly at relatively high revs.

The six-speed auto in the test car delivered crisp changes in full-auto mode and offered the driver the choice of manual shifting via steering wheel paddles or the regular console lever (forward for downshifts, backwards for upshifts). It may not be a dual-clutch manual, but is still efficient in transferring power to the road and is economical too.

On test, the 123d auto returned an average 6.0L/100km.

The chassis is complemented by the stiff body structure and standard 17-inch alloys to combine with the engine's ready punch for a decently sporty drive.

With just 2.9 turns from lock to lock, the convertible's steering is communicative, accurate and responsive with a nicely judged amount of weight as lock is applied.

And even though the engine lacks the aural charms of six-cylinder versions, there's plenty of torquey punch accelerating out of a corner and a few more revs to play with than you'd expect of a diesel. Rest assured the 123d convertible has the appropriate BMW dynamism.

The 123d convertible does have a problem, universal in all 1 Series BMWs, in that it doesn't carry a lot of fuel. At 51 litres, it holds even less than the 53-litre tank used in petrol versions and limits what would otherwise have been a truly impressive cruising range. It's still a diesel nevertheless and will, in theory, manage 800km or so on a tank -- around 200km better than, say, the 135i version.

The 1 Series has plenty of competition. It is right up there in price, equalled only by the larger four-seat Volvo's C70, but it is the only one with rear-wheel drive, the only one with a six-cylinder option -- and one of only three in its class to offer a diesel alternative.

Any one of those advantages could well swing a sale in the BMW's favour. Going for the 123d option, you forgo the smooth symphonics of the BMW sixes, but you still get genuinely solid performance, a decently low emissions figure -- and outstanding fuel economy.

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