Review

THE number of diesel- powered convertible cars on sale can currently be counted on one hand. In alphabetical order, there is the Audi A4 Cabriolet 2.5 TDI, the Citroen C3 Pluriel 1.4 HDi, the Renault Megane Coupe Cabriolet 1.9 dCi and finally the Volkswagen Beetle Convertible 1.9 TDI.

If you want to be pedantic, you could count the three-door Freelander Td4 with its ‘Softback’ or removable hardback specified, but as that allows only the rear-seat passengers to enjoy the full benefit of open-air motoring, I would argue it doesn’t count.

The range of proper diesel convertibles offered in the UK is about to be boosted by 25% with the introduction of a BMW 3-series convertible wearing a ‘d’ on its boot lid. Even with the addition of the BMW, diesel will still be spread rather thinly in the open-top sector. Of all car sectors, the ragtop is perhaps least suited to diesel engine.

In the past, the rattly nature of traditional diesels wouldn’t even warrant consideration in a convertible, but growing acceptance along with the more refined nature of modern diesel engines has meant that wind-in-the-hair motoring can be combined with fewer fuel stops.

However, perhaps a lack of awareness of diesel convertibles in both the retail and the corporate sector, BMW plans to sell only 900 diesel convertibles in the UK during 2005 following the car’s arrival in March.

This could also have something to do with the fact that it arrives just before the introduction of the all-new 3-series saloon, with the implication that the current generation 3-series convertible would have a year or so left before being replaced itself.

However, nearly 40% of total 3-series sales in the UK are diesels (based on 2004 year-to-date figures) and 34% of 3-series Coupes (on sale since late 2003 and boosted in March by the addition of the 330Cd) are diesel. The 3-series convertible has also witnessed significant growth, rising from 2,573 units in 2000 to nearly 9,000 in 2003. Registrations to the end of September 2004 put the running total at 6,926.

With 900 units planned for next year, aspirations seem modest, and putting a six-cylinder diesel engine in the car would appear to boost its desirability, but there is no short-term plan for a 330Cd Convertible, although it has not been ruled out in the future. A sensible prediction might be for a six-cylinder diesel variant when the next generation convertible arrives in 2006.

So, the first diesel 3-series convertible relies on the 2.0-litre second-generation common rail turbodiesel found in other models in the 3-series range. It boasts 150bhp at 4,000rpm and 243lb-ft at 2,000rpm.

Currently it only has one premium sector rival – the Audi A4 – whose 2.5-litre TDI engine has two more cylinders, slightly higher power and a little less torque than the BMW. It is a little cheaper at the front end at £27,450, but the BMW has an impressive array of standard equipment.

The SE has Dynamic Stability Control, parking sensors, cruise control, electrically adjustable seats, automatic climate control, four airbags (rear side airbags are optional) and a fully electric roof.

Parking sensors, electrically adjustable seats and cruise control are optional on the Audi A4, which gives the spec-adjusted price advantage to the BMW.

The Sport model adds M body styling, 18-inch M Sports alloy wheels (the SE has 16 in alloys), sports seats and an M Sports multi-function steering wheel and is priced at £30,675 on-the-road.

Options on both SE and Sport models include xenon headlights, two levels of satellite navigation and Active Steering.

BMW expects 70% of the 900 UK-bound models to be Sport variants.

BMW continues its three years/60,000 miles free servicing offer on all 3-series diesel models, and comparing the 320Cd Convertible to its petrol-fuelled 318Ci Convertible and 320Ci Convertible siblings, a 40% taxpayer could be saving anything between £35 and £110 a month in benefit-in-kind tax.

Behind the wheel

THE trick for any diesel convertible is to perform in such away that the occupants forget the negative aspects of the engine.

That low-down torque is all very well, but if the engine is chugging away like a tractor when you sit at traffic lights with the roof down it could be a major disappointment and embarrassment.

Luckily, the 2.0-litre diesel in the 3-series is one of the more refined on the market and while there is no mistaking it for a petrol engine from the noise it makes, it is certainly within acceptable levels for a premium convertible.

The diesel engine note becomes harder to detect as speed builds and you begin to enjoy the performance. Despite the extra weight from the retractable roof (this car weighs nearly one-and-three-quarter tonnes) the engine is responsive and always feels sprightly.

The six-speed manual transmission is business-like rather than slick, but the near-perfect balance and rear-wheel drive set-up that BMW keeps referring to in its TV ads really do make a difference.

The 320Cd Convertible seems to respond intuitively to every command and it is refreshing not to have the substantial diesel torque interfere with the steering, as it might in every other diesel convertible (all of which are front-wheel drive) on the market.

The 3-series convertible is still relatively fresh looking following its styling revisions about 18 months ago and the interior quality is first rate. Our SE test car also proved comfortable, despite the sporty driving experience. Opting for the Sport with 18-inch wheels would probably improve grip levels at the expense of low-speed ride and road noise, but drivers will decide their priorities and choose accordingly.

Premium convertibles tend not to suffer with scuttle shake these days and this car is no exception. The rear seats are rather tight for adults on longer journeys and the luggage compartment varies in capacity depending on whether the roof is up or down – keep the roof up if you have a lot to carry – but front seat occupants have more than enough space.

A useful accessory for chilly weather when two are travelling is the wind deflector, which sits behind the front seats and would be in the faces of rear seat passengers. But it makes a real difference to the amount of buffeting at speed.

Driving verdict

WITH just 900 units planned for the UK in 2005, the BMW 320Cd Convertible should be snapped up without any trouble.

It offers a significant cost advantage to fleets running a user-chooser policy and drivers will see the financial benefit of the efficient Euro IV diesel engine in their monthly BIK bills. It also combines elegance with real driver appeal.

Make: BMW
Model: 320Cd Convertible
Engine (cc): 1,995
Max power (bhp/rpm): 150/4,000
Max torque (lb-ft/rpm): 243/2,000
Max speed (mph): 131
0-62mph (sec): 9.7
Fuel consumption (mpg): 44.8
CO2 emissions (g/km): 167
Fuel tank capacity (l/gal): 63/13.9
Transmission: 6-sp man
Service interval: Variable
On sale: March 2005
Price (OTR): £28,350-£30,675

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