BMW M235i Convertible 2015 review

Drop the soft-top and you'll warm to this convertible - even in the cold

Being sandwiched between two B-doubles is never entertaining. The noise, the lack of peripheral vision and the sheer mass of the metal on either side tends to focus the attention on staying precisely in the middle of your lane.

Doing it in a convertible in Melbourne in June adds another couple of layers to the experience — not least the fact the trucks funnel the seasonably brisk wind straight at you.

Did I mention the top was down and the roads were wet, so that wind was laden with tiny droplets of road grime-infused water? Memo to self: don't wear white shirts when "topless".

Ah, the joys of open-air touring. The soft-top on this particular machine — BMW's new and shiny 2 Series convertible — takes 20 seconds to pop out of the boot and clamp on to the windscreen and can be operated at up to 50km/h (not that we'd recommend it).

Show a modicum of common sense and this convertible won't leave you feeling cold. The insulated fabric roof does a phenomenal job of masking the outside din and there's no need to raise your voice at freeway speeds.

In most other respects it is a typical two-door, four-seat convertible. The rear seats are hard to access and there's no room to move once in them; the boot is good for a set of golf clubs or some bags for a weekend away; and the roof's huge side panels and a tiny back window mean rear vision is pretty much non-existent.

It is the price you pay for buying a car as a fashion accessory and it is one many people are willing to accept. Love or loathe convertibles, people look at them and/or the people in them. Pop a kidney grille on the front and they look even longer.

BMW's latest looker has three tiers, from the 220i at $54,900 up to $85,800 for the M235i. The latter is the first BMW convertible to earn the M Performance upgrades and it's the one we're driving to see whether all that power can distort the 2 Series chassis.

The only real rival to the 2 Series convertible is Audi's A3 cabriolet line-up, headlined by the S3 performance variant. The all-wheel-drive S3 is half a second slower to 100km/h than the BMW ... but it's also $15,000 cheaper.

Equipment

Satellite navigation is standard on all models, as is cruise control with auto-braking to avoid rear-ending the car in front. Dual-zone aircon keeps the front occupants temperate, though the 220i misses out on front seat heaters. The M235i's screen grows from 6.5 to 8.8 inches and it packs a bigger sound system.

Performance

Outputs are up on all engines, matched to BMW's silky eight-speed automatic. Acceleration ranges from a respectable 7.6 seconds in the 220i to a rorty 5 seconds flat in the M235i. Hang on to your hairpiece.

Driving

Drivetrain modes range from the mushiness of Eco Pro to the twitch-responsiveness of Sport Plus, which even lets the tail hang out gently before reining it back in. The M division's work sets the 235i donor 10mm lower on stiffer suspension and it gains beefier brakes.

Design

Longer and wider than the outgoing 1 Series convertible, the new range retains the soft-top roof, which BMW says is now 50 per cent better at damping external sound. The boat-deck look with the roof down is still very evident and even when stowed the soft-top only uses 55L of the 355L boot.

On the road

Here's another free piece of advice for would-be convertible converts: keep clear of livestock trucks. The smell and the seepage don't interact well with top-down driving and if it is a cattle truck, they will stare at you in mute condemnation of the fact you're sitting on their relatives.

All of the above is still the case in a regular car but without a roof and windows the impact is more visceral. The corollary: when the sights and scents are more amenable, the convertible comes into its own.

Top-down driving tends to ruffle the hair unless the optional $570 wind deflector is fitted but surprisingly little cold air is driven farther down. Even on brisk mornings — and by brisk I mean single-digit temperatures — I was happy to drop the M235i's lid and let the seat heaters and aircon shield me from the chill.

The six-cylinder turbo is a bastion of the Beemer range, used in everything from the 1 Series to the X5. It is insane fun in any application, especially with an M Performance badge affixed to the bootlid.

In most applications this powerhouse is tuned for 225kW/400Nm but the wick has been turned up for 240kW/450Nm here.

It takes third world road surfaces and serious speed before you can feel the body flex

The issue then isn't how fast the M235i goes but how quickly the engine's torque can twist the compromised chassis. And compromised is a relative term, given the amount of buttressing and bracing hidden under the cabrio's panels, not to mention the fact it runs on lowered and stiffened M Sport suspension.

It takes third world road surfaces — of which Australia has a growing share — and serious speed before you can feel the body flex. Even then it is more shimmy than shake and certainly not going to throw you off line mid-corner.

What can catch you out is the engine's willingness to spin and slide the rear tyres in Sport Plus mode. It is progressive and endlessly repeatable without needing the reactions of a Formula One driver.

Find a series of corners that haven't been turned into corrugated bitumen and the M235i is as much fun as you can ask for this side of $100K. The $4900 limited slip diff is tuned to allow a bit of play before keeping the driver on the straight and narrow.