Blisteringly quick BMW M4 Convertible opens up to the sun.

Introduction

The folding hardtop makes the M4 Convertible unique in its class, but there are some slight trade-offs for its remarkable all-round ability, which includes near-supercar pace and intense handling, matched to easy everyday manners and four-seat practicality. 

Body Style: 2 door convertible Seats: 4  MRP from £63,180-£65,380

Did you know? BMW UK expects around half of M4 buyers to opt for the Convertible version

 

Verdict | Design | Interior | Technology | Performance | Safety | Specs | Running Costs | Pricing

Verdict: ★★★★★★★★☆☆ (7.5/10)

You once had to buy a supercar for the sort of pace the M4 Convertible brings, with BMW’s flagship 4 Series drop-top getting a serious performance boost courtesy of BMW’s M division engineers. Losing the roof does bring some small sacrifices when it comes to outright performance and agility, but they are so slight you’ll rarely notice them. Enjoy the sun instead, and its wicked pace, though newer rivals like the Mercedes C63 Cabriolet run the M4 Convertible very close, and in some ways now surpass it. 

Design & Exterior

★★★★★★★★☆☆ (8/10)

Interior & Comfort

★★★★★★★☆☆☆ (7/10)

Technology & Connectivity

★★★★★★★★☆☆ (8/10)

Performance & Handling

★★★★★★★★☆☆ (8/10)

Safety Features

★★★★★★☆☆☆☆ (6/10)

Spec & Trim Levels

★★★★★★★★☆☆ (8/10)

Running Costs & Fuel Economy

★★★★★★☆☆☆☆ (6/10)

Pricing

★★★★★★★☆☆☆ (7/10)

BMW M4 Convertible

We Like

Bold, assertive style

Firecracker of an engine. 

All-round capability.

We Don't Like

Slight performance penalty.

Steering lacks real feel.

Interior feeling a bit old now.

 

Verdict | Design | Interior | Technology | Performance | Safety | Specs | Running Costs | Pricing

Design & Exterior: ★★★★★★★★☆☆ (8/10)

Take the already sharp style of the BMW 4 Series, add a smattering of M badging, more assertive, sporting looks and standard 19-inch M light alloy double spoke wheels housed in larger wheel arches and you have the M4 Convertible. The standard 4 Series will turn heads, but the M4 will attract and retain attention thanks to its more muscular stance and M specific styling. The large air intakes up front project a more aggressive face to the world, and if you’re left in any doubt this is the performance flagship BMW’s added a sizeable bonnet bulge to underline the M4’s status.

Around the back again there’s no hiding the M4’s potential, either, even if you’ve sneakily opted for the free badge delete option. Four signature tailpipes are situated below the wider rear bumper while the bootlid is re-profiled significantly to exploit the air rushing over it. It’s unlikely, but if you find the standard M4 styling in any way lacking there’s always the opportunity to add to it with the Competition Pack. As well as some performance enhancing equipment choosing it adds some beautiful 20-inch M light alloy star spoke wheels and high gloss Shadowline (dark) trim as well as black chrome tailpipes. On top of that BMW offers exterior carbon styling packs, or black packs. Either way, the M4 Convertible’s looks don’t leave you in any way guessing at its performance, which is a huge part of its appeal.

BMW M4 Convertible

 

Verdict | Design | Interior | Technology | Performance | Safety | Specs | Running Costs | Pricing

Interior & Comfort: ★★★★★★★☆☆☆ (7/10) 

As with the exterior, take the standard 4 Series and give it an M sporting makeover. You’ll find M badging throughout then, on the sports seats (where they’re Illuminated) to the instruments and on top of the gearlever - whether you’ve gone for the standard six-speed manual or the optional DCT dual-clutch automatic transmission.

The seats are more heavily bolstered to hold you that little bit tighter, the rear, as other 4 Series models, being a pair. They’re quite tight on space, and if you’ve put the, optional, wind deflector in place then you effectively turn the M4 Convertible into a two-seater. The dashboard is all familiar, and being the range-topping model means some enhanced equipment, the M4 Convertible gaining the larger centre screen as part of the standard BMW Professional Media equipment package.

The suspension, like all the drive elements, is configurable, allowing a softer, more compliant ride when you want it, or firmer taut control if you’re intent on using all the M4’s performance. If you’re planning on dropping the roof even on cooler days, you’ll want the optional Convertible Comfort Package, that adds heating to the steering wheel, and a warm air blower at your neck on the already heated seats, as well as that essential wind deflector.  

Practicality 

Drop the roof and the already smaller boot reduces from 370 litres to just 220 litres. There’s some optional practicality on offer if you choose the load-through package, but really, you don’t buy an M4 Convertible if you’ve designs on carrying people or luggage regularly - you can buy an M3 Saloon for that. Even so, it’ll carry four adults at a push, though it’s better at two adults and a couple of children. Given the huge performance on offer, that it’s a genuinely useable day-to-day proposition is impressive, and the compromises you pay for that outrageous potential are relatively scant.

BMW M4 Convertible

 

Verdict | Design | Interior | Technology | Performance | Safety | Specs | Running Costs | Pricing

Technology & Connectivity: ★★★★★★★★☆☆ (8/10)

Given its status as the range-topping model it’s no surprise that the standard technology mix is richer than you’ll find a regular 4 Series Convertible. There’s standard BMW Professional Media, which brings improved sat nav, BMW TeleServices, Online Services and Remote Services all controlled via the familiar iDrive controller.

Enhanced Bluetooth connectivity with wireless charging and DAB audio are also included, as well as a WIFI hotspot, but you’ll still have to pay if you want Apple CarPlay, a TV tuner and Harman Kardon loudspeakers, as well as a M specific head-up display. Likewise, standard Park Distance Control, front and rear, can be improved with surround view cameras, and given how easily the M4 gathers pace ticking the checkbox for the optional Speed Limit Display might just be prudent.  

BMW M4 Convertible

 

Verdict | Design | Interior | Technology | Performance | Safety | Specs | Running Costs | Pricing

Performance & Handling: ★★★★★★★★☆☆ (8/10)

Performance

With its 3.0-litre turbocharged in-line six-cylinder engine developing 415bhp in standard tune, or 433bhp with the optional Competition Pack, it’s hardly a shock that the M4 Convertible’s performance isn’t lacking. The additional weight of the folding roof does dent the Convertible’s figures against its fixed head M4 and M3 relations, but with just 0.3 seconds difference you’ll have to be very switched on to notice the difference.

At its quickest, it’ll reach 62mph in just 4.3 seconds, that figure relating to a Competition Pack equipped car with the DCT automatic transmission. Shift your own gears and save a couple of thousand pounds by doing without the Competition Pack and you’ll take 4.6 seconds. Whatever way you have it, then, the M4 Convertible isn’t slow.

The engine’s a firecracker, too, it’ll rev hard, but there’s not the requirement for big revs for the M4 to perform, the two turbochargers resulting in prodigious pace at any point in the rev-counter needle’s arc. That’s aided by the turbocharged engine’s sizeable torque output, which peaks at 1,800rpm and hangs around until 5,500rpm. While the turbocharged six sounds good, BMW has had to use the audio system to enhance it, it lacking the sort of rousing, gutteral notes that define its closest Mercedes-AMG C63 Convertible rival. That AMG has a bigger, turbocharged V8 under its bonnet, too.

The purists among us love that as standard it comes with a six-speed manual, but the majority are bought with the seven-speed DCT (twin clutch) automatic. It does such a good job of shifting - whether left alone or via the wheel-mounted paddles yourself - and improves both performance and economy, making it a desirable choice. That’s arguably even more true with the M4 Convertible, which is likely to appeal to a slightly less hardcore buyer, if, of course, anyone buying a 400bhp+ drop-top can justifiably be described as so… 

Handling and comfort

While the Convertible roof might do little to impact on the M4’s performance it does manifest itself more readily on the car’s dynamic ability. That’s not just due to the effect of the additional mass it brings, some 230kg over the coupe, but also the loss of torsional rigidity that comes with it. Some of that additional weight is to counter the effect of losing the roof. BMW has added strengthening to the floor and windscreen, to help keep things stiff, but find a bumpy road and there’s still a trace of shimmer though the structure. 

It is not as sharp as the coupe, but again that’s relative, the M4 Convertible still has the capacity to thrill. Grip levels are high, traction good, though the sizeable torque from low revs can make for a sometimes tricky rear on wet or greasy winter roads. The solution by adding more power might seem odd, but adding the Competition Pack helps the M4 dynamically. Yes it brings more power, though no increase in torque, its changes to the Adaptive M Suspension with specific springs, dampers and anti-roll bars being instrumental in the dynamic improvements. Also helping are differing configurations to the Active M Differential, the DSC (Dynamic Stability Control system) and the various Driving Modes (Comfort, Sport and Sport+), the result being a more resolved M4 overall, that as much as the increased performance making it faster.

Even with the Competition Pack it lacks a bit of the immediacy dynamically of the Coupe, while the brakes too need a firmer push if you’re enjoying the thicker end of the M4’s performance. The steering itself isn’t overly informative, though it’s accurate, the weighting fine in normal modes. Avoid the Sport steering modes as all it does is bring heft at the wheel with no corresponding improvements elsewhere. Leave the steering in Comfort, and dial up the engine and transmission’s responses and the M4’s at its best, and that’s really very good indeed, though the Mercedes-AMG C63 Convertible runs it very close indeed.   

Recommended engine: M4 Convertible DCT Auto Competition Pack

0-62 MPH

4.3 seconds

Fuel economy

32.5 mpg

Emissions

203g/km

BMW M4 Convertible

 

Verdict | Design | Interior | Technology | Performance | Safety | Specs | Running Costs | Pricing

Safety Features: ★★★★★★☆☆☆☆ (6/10)

There’s no independent crash test data for the M4, in either Coupe or Convertible guises, but it should provide good protection in a crash. There’s a strengthened windscreen and pop-up roll-over bars behind the rear seats, it coming with driver and passenger front, side and head airbags as well as electronic stability and traction control systems. 

Where it’s lacking slightly is in the latest preventative systems, these increasingly standard equipment on premium models. You’ll need to spend more then if you want the reassurance of City Collision Mitigation, Forward Collision Warning, Lane Departure Warning and Preventative Pedestrian Protection. All of that comes bundled under the Driving Assistant package, which, in fairness, is a relatively inexpensive add on.

BMW M4 Convertible

 

Verdict | Design | Interior | Technology | Performance | Safety | Specs | Running Costs | Pricing

Specs and Trim Levels: ★★★★★★★★☆☆ (8/10)

Colours

Eight standard colours offer the M4 Convertible buyer a broad choice from the relatively mild whites and blacks to something a little bit more wild like red or orange. On top of that there’s four BMW Individual colours which increase choice, these being a classy selection of darker hues that add a premium to the list price. Of course, BMW M will paint it any colour you want it, though doing so doesn’t come cheaply, and it’ll add time to your order. 

Inside, there’s a choice of leather colours from sensible blacks and greys to indulgent red, mixed with technical trim materials and inserts. If those don’t appeal BMW Individual adds richer earthy tones for the leather upholstery, contrasting stitching and wood trims, though we’d give the latter a swerve.

Trim Levels

There’s only really one well-equipped trim level, though you could argue that the Competition Pack adds another. As standard the M4 comes with 19-inch alloy wheels, Adaptive M Suspension, Automatic Air Conditioning with two-zone control, DAB, Cruise Control, BMW ConnectedDrive, WIFI, LED headlights, sat nav, Park Distance Control, rain sensing windscreen wipers, automatic headlights, tyre pressure monitoring, heated front seats and metallic paint.

The Competition Pack adds 20-inch alloy wheels, recalibrated suspension with specific springs and dampers, revised driving modes, increased power (18bhp) and styling revisions like black tailpipes and high-gloss Shadowline exterior trim. Unlike the Coupe the M4 Convertible Competition Pack does without the lightweight M Sport Seats, though the price is adjusted accordingly to reflect this.     

Size and Dimensions

Length

4,671mm

Width

2,014mm

Height

1,386mm

Max towing weight unbraked - braked

n/a not rated for towing

BMW M4 Convertible

 

Verdict | Design | Interior | Technology | Performance | Safety | Specs | Running Costs | Pricing

Running Costs & Fuel Economy: ★★★★★★☆☆☆☆ (6/10)

Four hundred and fifteen bhp. Right? It’s not going to be cheap to run, though we doubt any M4 buyer doesn’t get into ownership without the reasonable expectation that they’ll have to spend a lot to enjoy it. Officially the M4 Convertible will return 32.5mpg in its most efficient guise (DCT auto equipped), the reality being that you’d have to drive it like a saint to get anywhere near that. Think early 20s then, and enjoy it. CO2 emissions, if they matter, are 203g/km (again, that a best figure). The manual is worse, on both counts, and the Convertible, by virtue of being the heaviest M4, is the least efficient of all M4s. Burn up those fossil fuels then, and drop the top and enjoy the warmer planet you’re helping create.

Reliability and servicing

As with its regular BMW models and M division relations the M4 Convertible comes with condition and usage based servicing, that’s dictated by the trip computer. BMW offers fixed-priced service packages, some including consumables like brakes pads, wiper blades and suchlike, it worth paying the extra for these if you’re going to drive it as it’s meant to be.

Minor

Variable - condition based

Major

Variable - condition based

BMW M4 Convertible

 

Verdict | Design | Interior | Technology | Performance | Safety | Specs | Running Costs | Pricing

Pricing: ★★★★★★★☆☆☆ (7/10)

There’s a circa £4,000 premium to have the sun above your head in the Convertible over its M4 Coupe relation. To that you can add nearly £2,700 for the DCT seven-speed automatic transmission. That Competition Pack is a worthwhile addition, too, adding another £2,200 to the list price. Mercifully, you can pretty much stop there, though it’s possible with wanton option ticking to have an M4 Convertible north of £80,000.

Recommendations 

Tech Junky

DCT auto optioned Competition Pack car with Surround View, Speed Limit Display and TV tuner.

Luxury Seeker

DCT auto equipped M4 Competition Pack with BMW Individual paint and interior options, as well as the Convertible Comfort Package.  

Car Enthusiast

While the DCT auto is very good, if you’re a purist an M4 Convertible with the standard six-speed manual is a must.

Rivals

Audi RS5

Yet to be revealed in convertible guise, but it’s only a matter of time. Huge performance, not such big grins.  

Mercedes-AMG C63 Cabriolet

A bombastic V8 soundtrack and dynamics to match, it’s a tough act to beat in this class. 

Alpina B4 S Bi-Turbo Convertible

Alpina does classy performance, and the B4 S Bi-Turbo has M4-like performance in a more understated package. A connoisseur’s choice.

 

BMW M4 Convertible