The 2-Series Convertible looks like what it is - a direct replacement for the open-topped 1-Series - but there have been quite a number of changes to help it battle the Audi A3 Cabriolet.

The new car is both longer and wider than the old one - it has slightly sharper styling (particularly at the front) and BMW says its body is noticeably stiffer, the latter being of considerable importance as BMW is renowned for its driving dynamics and high levels of engagement. The roof can also be folded and unfolded while the car is travelling at higher speeds.

For the first time, there's an M Performance variant called the M235i, along with two more petrol-engined models called the 220i and 228i, which have the same capacity but considerably different power outputs. Diesel fans are currently limited to the 220d. So how does the 2 Series Convertible measure up to the competition?

Performance

All the engines for the 2 Series Convertible are mated to a six-speed manual or, optionally, eight-speed automatic gearboxes. With a manual transmission the 220i and 220d (which have similar outputs of 181bhp and 187bhp respectively) share the longest 0-62mph time of 7.5 seconds, while the 228i can do the same run in 6.1 seconds and the M235i in 5.2. The automatic gearbox makes little difference to its performance, but it does bring the M235i's time down to five seconds flat.  The top speed is limited to 155mph in the 242bhp 228i and 322bhp M235i, while the others can both reach or exceed 140mph.

As the only six-cylinder car in the range, the M235i makes the best sound by some distance, particularly when you're revving it hard. The 220d, like other BMW four-cylinder diesels, can be quite rattly in town, though its noise fades well into the background at motorway speeds.

The eight-speed automatic gearbox is magnificent. The manual's shift quality is better than it was in previous BMWs but not as slick as it might be, and use of the clutch requires concentration to prevent stalling in low-speed starts.

Ride and Handling

The back-end of the higher-performance car can become squirrelly if you're using a lot of throttle in mid-corner

The suspension on the 220d and M235i (the only models so far made available to the UK motoring media) is quite soft and possibly a little bouncy, in sharp contrast to the stiffness of the tyres. Wheel sizes range from 17 to 20 inches, with a corresponding reduction in tyre sidewall, and even on the 18-inch wheels we've experienced, the tyres transfer bumps in the road to the cabin with unnecessary accuracy. This effect is more noticeable in town than it is in harder country driving, where the suspension makes more of a contribution to the ride quality. At higher speeds, the 220d is more likely to wander under the influence of road surface imperfections than the M235i is. The back-end of the higher-performance car can become squirrelly if you're using a lot of throttle in mid-corner, which you may find exhilarating or alarming according to your mood and personality.

Interior and Equipment

It would have been called a 1-Series if BMW hadn't changed its naming policy. The 1-Series name is now reserved for BMW's small hatchback. The 2-Series range includes the Convertible, the Coupe and, strangely enough, a front-wheel drive compact MPV.

Raising or lowering the roof requires nothing more than pushing or pulling a button on the centre console, and takes twenty seconds. It can be done at road speeds of up to 31mph, considerably higher than in the 1-Series. The new car also has a larger boot than its predecessor at 335 litres rather than 305. That's with the roof in place. Folded away, it takes up some of the luggage space but leaves a still useful 280 litres. If you need to carry longer objects, a through-load facility is available as an optional extra. Convertibles tend to have very limited room for rear passengers, but the 2-Series isn't at all bad in this respect and can carry four adults in reasonable comfort, as long as none of them is as much as six feet tall. We also found the front seats provide excellent side support. The 220i and 220d are available in Sport, Luxury and M Sport trim levels, while the 228i comes in M Sport form only and the M235i has its own specification. Standard equipment on all of them includes automatic air-conditioning, a multifunction steering wheel, Bluetooth connectivity, DAB digital radio and BMW Emergency Call, while the more expensive models come with Dakota leather upholstery. The M235i has a sportier suspension set-up to match its higher power output.

Cost

The M235i can be yours for under £38,000, though it's easy to push this up to beyond £45,000 if you're tempted by the many optional extras.

As you might expect, the 220d is the star performer here. Priced only £785 higher than the 220i, it has far better fuel economy and CO2 figures of 60.1mpg and 124g/km with the manual gearbox, and 64.2mpg and 116g/km with the automatic. In the latter form, Vehicle Excise Duty payments are £30 from year two onwards (all the others will set you back by a three-figure sum) and a Benefit In Kind rating of 21 per cent in the 2015-16 financial year. The best any of the petrol cars can do is 44.1mpg and 149g/km (220i automatic), while the M235i manual's 33.2mpg and 199g/km are beaten by some versions of the Porsche Cayman. Pricing starts at £29,180 for the 220i manual. The M235i can be yours for under £38,000, though it's easy to push this up to beyond £45,000 if you're tempted by the many optional extras.

Our Verdict

This is arguably the best-looking small convertible BMW has ever produced, and it combines the opportunity for wind-in-the-hair motoring with a surprising degree of practicality. The downside is that the driving experience, which far from being the "ultimate" as BMW once claimed for previous models, still needs work, though this may be less of an issue for people who want the Convertible than those who would prefer to own the Coupe.