30 Apr, 2008 5:05am James Disdale

Fourth generation M3 cabrio includes eagerly anticipated M Double Clutch Tansmission and a folding hard-top.


By taking off the roof, BMW lets buyers get closer to the stunning sound of the M3’s V8. The folding hard-top also means you don’t need to compromise refinement or handling. In fact, the new Convertible is arguably a more pleasant everyday choice than the harder-edged M3 coupé. The case for the semi-auto box is less clear-cut. You’ll be better off saving £2,590 and sticking with the slick six-speed manual.
With summer just around the corner, it’s open season in the performance car sector. Along with the first rays of sunshine has come a sprinkling of hot drop-tops – and the latest is the brand new BMW M3 Convertible.

Now in its fourth generation, the fastest 3-Series cabrio gets a folding hard-top for the first time, promising all-weather usability and coupé levels of refinement and chassis stiffness.

Just as important for performance fans is the 414bhp 4.0-litre V8 engine – which the drop-top shares with its coupé and saloon stablemates – along with the arrival of the eagerly anticipated semi-automatic gearbox. The M3 Convertible is the first BMW to get the new M Double Clutch Transmission (M DCT). Bosses claim the seven-speed set-up not only boosts performance, but also slashes fuel consumption and emissions.

There’s no mistaking this car for anything other than an M3. At the front is a deeper bumper with larger openings for additional cooling, while the bonnet gets a power bulge and extra vents. Look down the sides and you will spot the chunky wheelarches, and the chrome grilles in the front wings wear M3 logos. At the rear are distinctive quad tailpipes. Lowering the electrically operated roof takes 22 seconds, and once it’s stowed you can fully enjoy the vocal powerplant as it revs to an incredible 8,300rpm.

Even though the folding hard-top mechanism adds 23kg to the weight, performance is still impressive. With the M DCT transmission, the sprint from 0-62mph takes 5.1 seconds – that’s 0.2 seconds faster than in the standard manual six-speed model. Fuel economy rises from 21.9mpg to 23.0mpg, while CO2 emissions are reduced by 16g/km to 293g/km.

Drivers can fine-tune the gearshift with the DRIVELOGIC function. Five settings give a gradually more sporty response – the fastest option serves up ferociously rapid shifts with each pull on the wheel-mounted paddles. Unfortunately, changes can be jerky, even in full automatic mode.

With the metal hood in place the BMW’s chassis is 30 per cent stiffer than its predecessor’s, making the convertible nearly as agile as the coupé. It turns into corners keenly, suffers from minimal body roll and even has a supple ride. Only larger bumps will cause the body to shake and flex, although we were disappointed to find that the drop-top’s steering is slightly lifeless compared to its stablemate.

Inside, the cabin is lifted straight out of the coupé, and if it wasn’t for the thick-rimmed steering wheel and M-badged instrument dials, you could be in any 3-Series. Yet with the hood up, refinement is impressive – even at motorway speeds, the cockpit is well insulated from road and wind noise.

Despite carrying a £54,790 price tag, the M3 Convertible offers a lot of performance for the money. Add the £2,590 M DCT transmission, and it still undercuts the manual-only Audi RS4 by more than £2,000!

Key specs

* Price: £57,380 (with M DCT)
* Engine: 4.0-litre V8, 414bhp
* Gearbox: Seven-speed semi-auto
* 0-62/top spd: 5.1 secs/155mph
* Economy: 23.0mpg
* CO2: 293g/km
* Standard kit: Bi-xenon headlights, 18-inch alloys, variable diff lock, DAB, cruise and stability control, auto air-con, electric leather seats