BMW 4 SERIES CONVERTIBLE 420i M Sport 2dr Step Auto [Tech Pack]

BMW's second generation 4 Series Convertible has more appeal in this improved form. Jonathan Crouch takes a look.

Ten Second Review

The improved version of BMW's second generation 4 Series Convertible now has an even more distinctive look and a sporting dynamic feel. Inside, there's now more media tech and an even plusher cabin. The range has been severely slimmed down in this updated form, but for brand enthusiasts, there's still plenty to like. You won't get the large boot and cutting-edge driving dynamics of the 4 Series Coupe, but compensations come in the form of refinement, security and drop-top desirability. You'd like one.

Background

Echoing the bold style of its 4 Series Coupe showroom stablemate, the improved version of BMW's second generation 4 Series Convertible aims to blend sporting driving pleasure and open-air thrills to continue the 40-year legacy in this model class that began with the Munich maker's first 3 Series Convertible. As before, it sizes up to the same two segment arch-rivals, Audi's A5 Convertible and what's now called the Mercedes CLE Cabriolet - and like those competitors uses a fabric roof. With this smarter revised model, plenty of changes under the skin aim to make it a bit more of a driver's car than before.

Driving Experience

BMW has worked hard to ensure that this 4 Series Convertible's handling is as close to that of the equivalent Coupe as possible, using extra bracing and special panels to improve body rigidity. As usual with this model range, there's rear wheel drive and xDrive 4WD for the fastest models. There are no dynamic or engineering changes for this updated model, but BMW has slimmed down the powerplant range considerably, discontinuing diesel power and dropping the previous mid-level 430i petrol variant. That leaves only two mainstream models; the base rear-driven 184hp 420i; and the six cylinder 374hp M440i, which only comes in xDrive 4WD form. That six cylinder engine also features in 530hp form in the flagship M4 Competition variant, also only offered in xDrive guise. As before, there are firm springs and anti-roll bars, plus this Coupe gets a double-jointed spring-strut front suspension and a 5-link rear axle. All the engines link up as standard with eight-speed Steptronic auto transmission, which incorporates Launch Control for Grand Prix-style getaways. As previously, the M440i gets a Sprint function that gives you a steering wheel paddle that when activated, gives you an extra burst of acceleration. Toupees will need to be very firmly tied down. Arguably, less is more here - it's the rear-driven 420i that gets closest to BMW's traditional mid-sized coupe driver's formula. Rivals have long tried to copy this variant's front engine, rear wheel drive BMW layout with its near perfect 50:50 weight distribution - but never quite managed to deliver a package with the same kind of involving finesse. Super-effective traction and stability systems keep those back wheels in check so that if you're not a driving enthusiast, it'll all feel quite normal. But if you are, then the feeling of being propelled up the road by the back wheels as you exit a bend rarely fails to offer up a great feeling of pleasure.

Design and Build

When this MK2 4 Series Convertible first arrived, we were all talking about its rather inevitable switch from the previous model's metal hard top roof to the same kind of folding fabric top that rivals Audi and Mercedes offer. That meant a 40% reduction in roof weight from a soft top that uses panel bow elements and a glass rear window for optimum acoustic and thermal comfort. The electric folding roof takes 18 seconds to open or close and can be used at speeds of up to 31mph. With the revised version of this MK2 model, BMW wants us to talk about the car's redesigned LED headlights, with their smarter illumiating signature. That once-controversial grille is now surrounded by matte chrome and there are restyled front and rear bumpers too. Customers can add in the 'laser' rear lighting units first seen on the rare M4 CSL, plus there are restyled 19-inch wheel designs. And the top M440i gets black exterior design elements and horizontal bars within the kidney grilles. The CLAR mixed steel-and-alloy platform that underpinned the previous version of this car is retained, but BMW has tried to reduce its weight through greater use of aluminium panels. Inside, the air vents have been redesigned, as has been the steering wheel, which is now flat-bottomed and has standard shift paddles for the auto gearbox. As before, the 'BMW Live Cockpit Professional' dash set-up is standard, offering a fully digital screen layout that gives you a high-resolution 12.3-inch instrument cluster behind the steering wheel and a 10.25-inch iDrive infotainment Central Control Display, which now runs the brand's latest OS 8.5 software system, which gives you more customisation options. There's also enhanced voice control for the climate functions. As before, this is billed as a 'proper four-seater', though the rear seat isn't as comfortable as in the Coupe. Predictably, there's not as much boot space either, the Coupe variant's 440-litre capacity figure falling to 385-litres with the roof closed and 300-litres with the top down.

Market and Model

Sporty 'M Sport' trim is standardised and prices start from around £50,000 for the entry-level 420i, which means a big price premium of almost £7,000 over the equivalent Coupe model. Think in terms of around £65,000 if you want the M440i xDrive model. The top M4 Competition Convertible M xDrive model is around £88,000. Equipment levels have been subtly upgraded. Ambvient lighting's now standard and upholstery comes in a new velour the brand calls 'M Performtex'. Optional is Sensatec perforated manmade leather - or real quilted Vernasca leather. Interior trim strips in Aluminium Rhombicle Anthracite are standard, whilst Fineline Light Brown open-pored and Grey Blue Ash open-pored fine-wood trim, and M interior trim carbon fibre are available as options. Customers can also now have the gear selector lever, iDrive Controller and Start/Stop button in a 'CraftedClarity cut-glass finish. A Personal eSIM comes as standard with the car, in addition to its built-in mobile SIM. This enables the vehicle to use the 5G mobile communications standard. The Personal eSIM allows the customer to use the communications and connectivity functions covered by their mobile contract from their car with ease - even in situations where they don't have their smartphone with them. This also includes data streaming via the WiFi hotspot. Wheel sizes vary between 18 and 20-inches and among the options are an M Performance front ornamental grille and M Performance side sill attachments, both in carbon fibre. Interior equipment highlights include the M Performance seat back pans in Alcantara/carbon fibre, the M Performance interior trim strips in carbon fibre and the M Performance door sill trims, also in carbon fibre.

Cost of Ownership

As before, mild hybrid technology is included with both the mainstream engines. Fitting a 48V starter-generator and second battery greatly increases the scope for utilising Brake Energy Regeneration and the electrical power it produces. The recuperated energy collected by the 48V battery can be supplied to the 12V electrical system or used for generating additional drive power when fed back to the 48V starter-generator. When the car is accelerating, the generator is also able to offer the driver an electric boost effect that instantly makes an extra 11hp available. All of which should promise a very competitive set of efficiency stats. Let's see. The 420i is rated at between 46.3 and 49.6mpg on the combined cycle and 140-131g/km of CO2; for the six cylinder M440i xDrive, it's 38.2-40.9mpg and 169-159g/km. For the M4 Competition xDrive Convertible, it's 27.7mpg and 231g/km. Residual values? Well we expect the depreciation on this facelifted second generation 4 Series Convertible to be pretty similar to that of its direct predecessor, which would mean a very competitive retained worth of about 45% after three years and 60,000 miles. On to the warranty package. BMW's warranty only lasts for three years but it includes an Emergency breakdown service and at least it isn't mileage limited - unlike the comparable package you'd get as standard with a rival Audi. You can of course extent the warranty with either monthly or annual payments. There's a three year paintwork warranty and the usual 12 year anti-corrosion warranty.

Summary

Like many of its owners will be, BMW is quietly satisfied with this 4 Series Convertible, especially in this revised form. Would this car be a more engaging driving machine without the extra weight of its roof mechanicals? The extra sharpness of its 4 Series Coupe stablemate certainly suggests that. I sense though, that most buyers of this open-topped version will be quite happy with a more relaxed, comfortable demeanour. That is, after all, as much as competitors from Audi and Mercedes offer - and those brands can't deliver the engine choice BMW provides here. In fact, a lot of boxes are ticked by this car if you can afford its asking price. You get impressive safety systems, high residual values, above average rear seat legroom and a sheer depth of engineering that rarely fails to impress. As a result, in many ways, it's probably the most complete contender in this segment and, best of all, it looks as striking and expensive as a convertible of this kind should when the sun's out and all is right with the world. True, there are probably all kinds of ways of more sensibly spending the budget required for one of these. You know what though? Right here, right now, I can't really think of any....

Body Glass

Acoustic glazing

Automatic windscreen wipers and automatic headlight

Electric windows - front and rear, with open/close fingertip control, anti trap facility and comfort closing function all round

Green tinted heat protection glazing

Windscreen washer jets concealed underneath bonnet

Brakes

Brake energy regeneration

Braking pre-tensioning

Dry braking

Dynamic brake control

Dynamic stability control + (DSC+) - Anti-lock Braking System (ABS) with brake assist and cornering brake control + Automatic Stability Control (ASC)

Dynamic Traction Control - DTC

Electric parking brake including automatic hold function and automatic release of the parking brake when driving off

Front and rear ventilated brake disc

Hill start assistant

Carpets/Rugs

Velour front floor mats

Chassis/Suspension

Double joint spring strut front axle

Drive experience mode switch - Comfort mode, ECO PRO mode and SPORT mode

Low centre of gravity

Stroke dependent dampers

Driver Aids

Automatic start/stop function

Driver Convenience

Active guard plus

Attentiveness assist

Variable sport steering

Driver Information

BMW ConnectedDrive online services

BMW iDrive controller on centre console

BMW service history

BMW Teleservices

Brake pad wear indicator in front and rear

Check Control warning system for monitoring of lights and door/luggage compartment open warning

Condition based service

Instrument cluster with speedometer with mph readout, tachometer, fuel gauge and oil temperature gauge

Integrated owners handbook

Language version English

Oil sensor for level and grade

On board computer - average speed, fuel consumption, outside temp display with acoustic warning, clock/date, service interval, odometer/trip meter

Run flat indicator

Shifting point display

Driving Mirrors

Electric folding wing mirrors - Driver side electrochromic, auto anti dazzle function & front passenger side auto parking function without anti dazzle

Interior rear view electrochromatic mirror with automatic anti dazzle function

Embellishment Trims

Luxury instrument panel - Instrument panel and door upper arm trim panels in sensatec, black grey contrast stitching

Engine

Balanced 50/50 weight distribution

Electronic differential lock control (EDLC)

Petrol Particulate Filter

Entertainment

DAB tuner

Personal eSim

Exterior Body Features

BMW radiator grille with mesh grille, end face of the nuggets in aluminium matt and frame in chrome matt

Body colour fuel filler flap

Body colour roof fin

Bonnet and tailgate badge

Front and rear bumper system

Front apron plastic in body colour

Illuminated bow type door handles in body colour drivers side with door lock

Licence plate panel integrated into front bumper and tailgate

M designation on front side panels, left and right

M Sport entry door sill strips

Model designation on right side of tailgate

One piece front bumper cover including towing eye cover in body colour

Rear boot

Side frame trim strip black matt

Visible exhaust tailpipe finisher

Visible VIN plate

Widened track and increased camber values for max transverse dynamics, agility and steering precision

Wind deflector

Exterior Lights

Automatic headlight beam throw control with load dependent regulating reaction, dynamic compensation of braking dive and acceleration squat

Follow me home headlights

LED 3rd brake light

LED daytime running lights

LED front fog lights

LED front indicators

Preparation for high beam assistant

Reversing light

Two part LED tailights in L-shape with components in smoked glass, brake light, LED turn indicator and rear fog light

Welcome lights in interior and door handle area

Heating/Cooling/Ventilation

2 zone automatic air conditioning

Interior Features

12V power socket in front centre console

2 front cupholder in centre console with clamping elements and matt black inlay

3 spoke flat bottom M sport leather multifunction steering wheel

4 pieces lashing eyelets in luggage compartment

Anthracite headlining

Armrest integrated in front and rear door trim + front centre console armrest

Battery in luggage compartment

BMW ID

Extended storage - Luggage compartment partition net on left side trim panel, Bag hook on both sides of the luggage compartment

Front and rear door pockets

Illuminated glove compartment with separate small compartment

Steering column adjustment - Infinitely variable in height and length

Toolkit located in luggage compartment

Interior Lights

Front footwell lights

Illuminated armrest storage compartment

Interior light and front reading light

Luggage compartment light

Packs

Ambient lighting pack - 4 Series

Connected professional package - 4 Series

M High gloss shadowline exterior trim pack - 4 Series

M sport exterior styling pack - 4 Series

Safety

2 x 3-point rear seatbelts

BMW emergency call

Child seat ISOFIX attachment for the two outer rear seats

Crash sensor activating of airbags, Unlocking doors, hazard warning lights, interior light, safety battery terminal

Driver and front passenger side airbags, integrated in the door side seat backrest bolsters for all seat variants

Driver/Front Passenger airbags

Front passenger manual airbag deactivation

Head airbags for all 4 outer seats

Seat belt security check for driver and front passenger

Seat belt with belt stopper, pyrotechnic belt tensioners and belt force limiters

Seat occupancy detection for driver and passenger side

Side impact protection

Tyre pressure sensors

Warning triangle and first aid kit

Seats

2 2nd row folding seats

2 Rear seat headrests

Electric memory seats - electrically adjustable seats with drivers seat memory, exterior mirrors memory and automatic parking function

Front sports seats

Heated driver and front passenger seats

Height adjustable front headrests

Single front passenger seat

Security

Alarm system for monitoring doors, engine compartment,interior movement sensor,tilt sensor and siren with emergency power supply

Centre lock switch - Button in driver's side front door, complete locking of car

Closing system with centre locking for all doors, fuel filler flap&tailgate, auto lock after pulling away, incl. 2 remote controls with integrated key

Electronic vehicle immobiliser

Locking wheel bolts

Vehicle key with M specific designation

Transmission

8 speed automatic steptronic transmission with gearshift paddles

Vanity Mirrors

Sunvisors with illuminated vanity mirrors and ticket pocket

Wheels - Spare

Tyre repair kit plus

Emissions - ICE

CO: 0.237

HC: 0.018

HC+NOx: N

Noise Level dB(A): 67

NOx: 0.018

Particles: 0.0002

Standard Emissions: EURO 6

WLTP - CO2 (g/km) - Comb: 154

WLTP - CO2 (g/km) - Comb - TEH: 158

WLTP - CO2 (g/km) - Comb - TEL: 154

WLTP - CO2 (g/km) - Extra High: 150

WLTP - CO2 (g/km) - Extra High - TEH: 158

WLTP - CO2 (g/km) - Extra High - TEL: 150

WLTP - CO2 (g/km) - High: 133

WLTP - CO2 (g/km) - High - TEH: 139

WLTP - CO2 (g/km) - High - TEL: 133

WLTP - CO2 (g/km) - Low: 212

WLTP - CO2 (g/km) - Low - TEH: 219

WLTP - CO2 (g/km) - Low - TEL: 212

WLTP - CO2 (g/km) - Medium: 157

WLTP - CO2 (g/km) - Medium - TEH: 164

WLTP - CO2 (g/km) - Medium - TEL: 156

Emissions - Lifecycle

End-of-Life Emissions - CO2e (Equivalent) - tonnes: 0.5

In-Life Emissions - CO2e (Equivalent) - tonnes: 35.2

Lifetime Emissions - CO2e (Equivalent) - tonnes: 44.9

Production Emissions - CO2e (Equivalent) - tonnes: 9.2

Engine and Drive Train

Camshaft: DOHC

Catalytic Convertor: No

CC: 1998

Compression Ratio: 11.0:1

Cylinder Layout: IN-LINE

Cylinders: 4

Cylinders - Bore (mm): 82

Cylinders - Stroke (mm): 94.6

Engine Code: B48B20M1

Engine Layout: NORTH SOUTH

Fuel Delivery: TURBO INJECTION

Gears: 8 SPEED

Number of Valves: 16

Transmission: SEMI-AUTO

Fuel Consumption - ICE

EC Directive 1999/100/EC Applies: 0

WLTP - FC (l/100km) - Comb: 6.8

WLTP - FC (l/100km) - Comb - TEH: 6.9

WLTP - FC (l/100km) - Comb - TEL: 6.8

WLTP - FC (l/100km) - Extra High: 6.6

WLTP - FC (l/100km) - Extra High - TEH: 6.9

WLTP - FC (l/100km) - Extra High - TEL: 6.6

WLTP - FC (l/100km) - High: 5.8

WLTP - FC (l/100km) - High - TEH: 6.1

WLTP - FC (l/100km) - High - TEL: 5.8

WLTP - FC (l/100km) - Low: 9.3

WLTP - FC (l/100km) - Low - TEH: 9.6

WLTP - FC (l/100km) - Low - TEL: 9.3

WLTP - FC (l/100km) - Medium: 6.9

WLTP - FC (l/100km) - Medium - TEH: 7.2

WLTP - FC (l/100km) - Medium - TEL: 6.9

WLTP - MPG - Comb: 41.5

WLTP - MPG - Comb - TEH: 40.9

WLTP - MPG - Comb - TEL: 41.5

WLTP - MPG - Extra High: 42.8

WLTP - MPG - Extra High - TEH: 40.9

WLTP - MPG - Extra High - TEL: 42.8

WLTP - MPG - High: 48.7

WLTP - MPG - High - TEH: 46.3

WLTP - MPG - High - TEL: 48.7

WLTP - MPG - Low: 30.4

WLTP - MPG - Low - TEH: 29.4

WLTP - MPG - Low - TEL: 30.4

WLTP - MPG - Medium: 40.9

WLTP - MPG - Medium - TEH: 39.2

WLTP - MPG - Medium - TEL: 40.9

General

Alternative Fuel Qualifying: 0

Badge Engine CC: 2.0

Badge Power: 184

Based On ID: N

Coin Description: i

Coin Series: M Sport [Tech pk]

Did at least one aspect of this vehicle's safety give cause for concern?: 0

Generation Mark: 2

Insurance Group 1 - 50 Effective January 07: 32E

NCAP Adult Occupant Protection %: N

NCAP Child Occupant Protection %: N

NCAP Overall Rating - Effective February 09: N

NCAP Pedestrian Protection %: N

NCAP Safety Assist %: N

Service Interval Frequency - Months: 24

Service Interval Mileage: 18000

Special Edition: 0

Special Order: 0

Standard manufacturers warranty - Mileage: 999999

Standard manufacturers warranty - Years: 3

Timing Belt Interval Frequency - Months: N

Timing Belt Interval Mileage: N

Vehicle Homologation Class: M1

Performance

0 to 60 mph (secs): 0

0 to 62 mph (secs): 8.2

Engine Power - BHP: 184

Engine Power - KW: 135

Engine Power - PS: No

Engine Power - RPM: 5000

Engine Torque - LBS.FT: 221

Engine Torque - MKG: 30.6

Engine Torque - NM: 300

Engine Torque - RPM: 1350

Top Speed: 147

Test Cycles

Emissions Test Cycle: WLTP

RDE Certification Level: RDE 2

Tyres

Alloys?: No

Space Saver?: 0

Tyre Size Front: 225/45 R18

Tyre Size Rear: 225/45 R18

Tyre Size Rear: 255/40 R18

Tyre Size Spare: TYRE REPAIR KIT

Wheel Style: DOUBLE SPOKE STYLE 848M

Wheel Type: 18" ALLOY

Vehicle Dimensions

Height: 1384

Height (including roof rails): N

Length: 4768

Wheelbase: 2851

Width: 1852

Width (including mirrors): 2081

Weight and Capacities

Fuel Tank Capacity (Litres): 59

Gross Vehicle Weight: 2185

Luggage Capacity (Seats Down): N

Luggage Capacity (Seats Up): 385

Max. Loading Weight: 495

Max. Roof Load: N

Max. Towing Weight - Braked: 1600

Max. Towing Weight - Unbraked: 750

Minimum Kerbweight: 1690

No. of Seats: 4

Turning Circle - Kerb to Kerb: 11.4

Brakes

M Sport braking system with blue painted brake calipers + M designation

Chassis/Suspension

Adaptive M suspension

Driver Convenience

Active cruise control with stop and go

Embellishment Trims

Ash grey-blue fine wood open poured interior trim - dashboard

Carbon fibre interior trim

Galvanic embellisher for controls

Light fine wood open pored interior trim - dashboard

Entertainment

Harman/Kardon surround sound audio system

HiFi loudspeaker audio system

Exterior Body Features

BMW Individual frozen paint work

BMW Individual metallic paint work

BMW Individual special request paint

Metallic paint

Exterior Lights

Adaptive LED Headlights

BMW adaptive LED headlights

High beam assistant

Heating/Cooling/Ventilation

Warm air collar

Hoods

Soft top - Anthracite silver with opening/closing function up to 30mph

Interior Features

BMW Individual extended Merino leather upholstery

Crafted clarity for interior elements

Heated steering wheel

Sensatec perforated artificial leather upholstery

Vernasca leather upholstery II

Packs

Comfort pack I - 4 Series Convertible

Technology pack I when bought with Driving assistant professional package - 4 Series

Paint - Metallic

Metallic - Arctic race blue

Metallic - Black sapphire

Metallic - Brooklyn grey

Metallic - Cape York green

Metallic - Fire red

Metallic - Mineral white

Metallic - Portimao blue

Paint - Solid

Solid - Alpine white

Paint - Special

BMW Individual frozen paint - Portimao Blue

BMW Individual metallic paint - Dravit grey

BMW Individual metallic paint - Tanzanite blue

BMW Individual paint - Special request

Seats

Front seats electric adjust lumbar support

Towing

Towbar

Trim - Leather

BMW individual extended Merino leather - Tartufo

BMW Individual extended Merino leather - Black

BMW Indvidual extended Merino leather - Ivory white

Sensatec perforated artificial leather - Black

Sensatec perforated artificial leather - Cognac

Sensatec perforated artificial leather - Tacora red

Vernasca leather - Black with blue stitching

Vernasca leather - Black with grey stitching

Vernasca leather - Mocha with night blue stitching

Vernasca leather - Oyster with grey stitching

Vernasca leather II - Black with red stitching

Wheels - Alloy

19" BMW Individual Y spoke bicolour frozen midnight grey light alloy wheels - Style 1038I with mixed tyres

19" M double spoke bicolour jet black light alloy wheels - Style 995M with mixed tyres

19" M double spoke jet black light alloy wheels - Style 995M with mixed tyres