The basic petrol engine is the 320i - the only four-cylinder petrol in the line-up. It's smooth and quiet but enjoyable to drive with a 0-60mph time of 8.8 seconds and a top speed of 142mph. The 325i brings the 0-62mph time down to 7.4 seconds and the top speed up to 152mph and is one of the best engines in the line-up. It sounds delightful and has a responsive and sporty nature, yet still manages to deliver 37mpg.
The 330i actually uses the same 3.0-litre engine as the 325i, but tuned to deliver 272bhp and significantly more pulling power. However even this can't match the superb 335i engine. This is also a (different) 3.0-litre unit but uses twin turbochargers to produce 306bhp and oodles of in-gear pace - as a result it is an absolute delight to drive with endless acceleration and instance throttle response.
A 0-62mph time of just 5.8 seconds ensures it's only half a second slower than the immense M3 but it still capable of 28mpg. There are three diesels on offer with the entry-level 320d model capable of 53mpg. The 325d and 330d actually use the same 3.0-litre six-cylinder diesel engine, but with differing power outputs of 197bhp and 231bhp respectively.
The latter is certainly rapid enough for most with a 0-62mph time of 7.0 seconds while huge amounts of grunt make it sublime on the motorway and when it comes to overtaking.
The 3-Series Convertible ticks all the right boxes when it comes to driving pleasure, despite weighing 200kg more than the coupe due to the integration of the folding roof mechanism. It's surefooted, corners with little roll and is at it's best on B-roads, where it changes direction with composure and precision. The steering is exemplary - it's sharp, accurate and well weighted - and the brakes are responsive.
As is common with other BMWs, the ride has a firm and sporty feel to it, however, it still remains surprisingly comfortable for longer journeys.
All-round visibility with the roof up is very good for a convertible - the forward view is clear and there's a particularly large rear screen at the back. The driving position is excellent with plenty of adjustment (all of which is electric) and the steering wheel adjusts for height and reach. BMW's i-Drive system - which controls the sat nav, phone and stereo functions (among others) is standard.
It takes a little getting used to, but is surprisingly easy to use once mastered.
There’s enough legroom in the back for two adults to sit comfortably, plus adequate headroom whether the roof is raised or not. On the move, it's quiet and refined and with the roof down, it's hushed enough to hold a conversation on the motorway. Plus, unique to BMW, is special sun reflective leather upholstery that’s said to remain up to 20 degrees cooler than standard leather in direct sunlight.
It means that on hot days, the roof can be left down without the worry of uncomfortably hot seats.