BMW 6-Series Convertible (2004-2010) engines, drive and performance
Early cars were offered with just one engine, a 4.4 V8 (645i) with 333bhp and a 0-62mph time of just 5.9 seconds. Not only does it sound wonderful but the power delivery is effortless, with acceleration throughout the rev range. Late 2004 saw the arrival of the six-cylinder 3.0 V6 (630i) – it’s not as potent as the 4.4 V8, but still quick and you expect to see 62mph in 6.7 seconds.
In autumn 2005, the 4.4 V8 was replaced with a 4.8 V8 (650i). It’s fantastically smooth, a joy to drive and offers similar performance to the 4.4 V8. In late 2007 the 6-series received a minor facelift and a new addition to the line-up – the 635d. This sole diesel option is a fraction quicker than the 630i (0-62mph in 6.6 seconds) and more frugal with a claimed average of 39mpg.
It offers huge amounts of low down pulling power and as a result in-gear performance is superb. This blend of real-world performance and affordable running costs makes the 635d the pick of the range.
As the Convertible 6-Series was developed alongside the Coupe, rather than afterwards, it’s little surprise that there’s few differences between the two when it comes to handling. Even with the roof down the 6-Series Convertible has great poise and is surefooted through corners with excellent traction too. Despite lacking a solid roof there’s practically no flex in the body and there are no nasty vibrations through the cabin when tackling bumpy or rough roads.
The brakes are superb and buyers can choose the optional Active Steering which makes it sharp for A and B roads but needs smaller inputs on the motorway. Three gearbox options are offered – a standard six-speed manual, the optional Sports Automatic transmission (standard on the 635d) or the excellent sequential manual gearbox, better known as SMG.