2021 (71) BMW 4 Series 420i M Sport 5dr Step Auto

BMW's 4 Series Gran Coupe has evolved nicely in second generation form. Jonathan Crouch takes a look at the revised model.

Ten Second Review

The improved version of BMW's second generation 4 Series Gran Coupe offers a more flexibly stylish choice in the profitable sector for premium badged Gran Turismo-style mid-sized executive cars. For once, two rear doors don't compromise the visual appeal of a model of this kind, nor does their extra weight dilute the handling purity. Of course, there are more practical choices in this segment - and certainly cheaper ones. After trying this BMW though, you might not be quite so attracted to them. For brand enthusiasts, there's certainly plenty to like.

Background

Electric cars are the future. But, for most people, not quite yet. Which is why at present, we find ourselves in this curious hinterland where brands must build, design and market the same kind of car both in combustion form and as an EV. Take the model in question here, the second generation version of BMW's 4 Series Gran Coupe, launched in 2021 and subtly updated in Spring 2024 to create the car we look at here. It's a GT-style mid-sized premium executive challenger; just like the brand's i4, launched (and now updated) at about the same time, based on the same CLAR platform and built at the same Munich factory. To be fair, the 4 Series Gran Coupe is visually differentiated fom its EV stablemate and also has an interior that's different from the i4 because the front of cabin design borrows everything from the two other 4 Series models BMW offers, the two-door Coupe and the Convertible. As with those two cars, the Munich maker has worked hard to make both the styling and the drive experience more distinct from the closely related 3 Series model. Let's find out more.

Driving Experience

As part of this update, BMW has reduced the 4 Series Gran Coupe line-up down to just two models, both petrol-powered. There's the rear-driven entry-level 420i with 184hp and a four cylinder engine which makes 62mph in 7.9s. Or the six cylinder M440i, which uses the brand's xDrive 4WD system and develops 374hp. This makes 62mph in just 4.7s. Both the engines feature the brand's mild hybrid 48V tech and link up as standard with eight-speed Steptronic auto transmission, which on the 420i can be specified with an optional Sprint function. Even in standard form, this transmission is ultra-slick in its changes and now gets standard gearshift paddles. The mild hybrid system uses a 48V starter generator and makes output of 11hp instantly available in response to the slightest movement of the accelerator. This electric boost enhances the drive system's dynamic response when accelerating off the line and putting in mid-range bursts of speed. The electric drive unit also assists the engine when travelling at a constant speed, allowing it to operate within an efficiency-optimised load range as often as possible. Handling of both models is aided by a wide track and near-perfect 50:50 weight distribution. On standard suspension, this '4' rides 10mm lower than a BMW '3'. The chassis has been extensively tweaked over that of the 3 Series and there are firmer springs too - and anti-roll bars and clever lift-related dampers reduce body movement and sharpen corner turn in. Plus there's a clever double-jointed spring-strut front suspension and a 5-link rear axle.

Design and Build

The exterior changes made to this updated model are uber-subtle. The headlights now get a sharper look, with the low and high beams now generated from a single LED module. There's also smarter matt chrome kidney grille surround and silver mesh air intakes. Plus there are bigger exhausts which have increased in diameter from 90mm to 100mm. Otherwise, the look of this car is much as before, the front end dominated by BMW's controversial large kidney grille. It's an aerodynamically optimised design that includes a completely sealed underbody and an air flap control system in the grille. BMW has tried to reduce the weight of the CLAR mixed steel-and-alloy platform through extensive use of aluminium panels. Inside, the updates are equally subtle. There's a smaller gear selector and more minimalist reshaped cabin control air vents that utilise smaller rotary switches. Plus there's an updated flat-bottomed steering wheel which now features illuminated buttons and standard gearshift paddles. Perhaps a more significant change is the software upgrade to the 10.25-inch central monitor, which now uses BMW's 'iDrive 8.5' infotainment system. As before, the 'BMW Live Cockpit Professional' dash set-up is standard, offering a fully digital high-resolution 12.3-inch instrument cluster, which you're positioned in front of by supportive sports seats and above which you can view an optional head-up display. In the back, two adults can be accommodated reasonably comfortably as long as they're not too tall, but three would be difficult to take given the relatively high centre transmission tunnel. Boot space is rated at 470-litres, with 1,290-litres available by folding the rear bench.

Market and Model

Prices start from around £45,500 for the base 420i version and 'M Sport' trim is standard. As an option, there's an 'M Sport Pro' package which includes a special 'Sprint' function for additional bursts of speed and a sporty engine soundtrack in the cabin when the 'SPORT' driving mode is activated. Plus you get M sport brakes, 19-inch 'M light' alloy wheels, a rear spoiler in a high-gloss black, BMW individual high-gloss 'Shadowline' trim with extended features and BMW individual lights and M seat belts. It's well over £65,000 for the alternative M440i xDrive performance variant. Even on the 420i, as you'd expect for the money being asked here, you get a full rosta of luxury segment features: full-LED headlamps, acoustic glazing, ambient lighting, 40:20:40 split-folding rear seat backs and 3-Zone climate control. There's loads of help for slotting this car into tight bays too, not only all-round sensors and a reversing camera but also a 'Parking Assistant that automatically steers you into parallel or perpendicular spaces and a 'Reversing assistant' that when you return after parking up, can automatically reverse you along whatever path you've previously taken forward. With the M440i, there's the standardisation of BMW's 'M Sport differential', plus free-form exhaust tailpipe finishers and a cooler 'Cerium Grey' finish for the Air breathers, the kidney grille, the mirror caps and the model designation badgework. You get a specific cockpit design too.

Cost of Ownership

Mild hybrid technology has been included with both engines - even with the straight-six petrol unit of the flagship BMW M440i xDrive Gran Coupe. 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 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 competitive set of efficiency stats, though they're way down on what you'd get from an identically-engined 4 Series 2-door Coupe. We'll start with the 420i, which manages up to 41.5mpg on the combined cycle and up to 154g/km of CO2. For the M440i xDrive, the figures are up to 32.8mpg and up to 194g/km. 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

One great car can create many such models. Certainly, there seems to be an almost never-ending series of ways that BMW can use the underpinnings of their segment-defining 3 Series saloon to suit ever-changing customer preferences. Here perhaps, in this good looking second generation 4 Series Gran Coupe, we have the most appealing example of what this Munich maker can do in the mid-sized executive segment. Not all cars that claim to be 'coupes' are stylish enough to really deserve that title - particularly those that must also accommodate two rear passenger doors. This improved Gran Coupe though, wears its badge credibly yet still offers enough practicality to justify its existence. Overall, if you're looking at buying a conventional premium badged mid-sized executive model, you may well not already have this Gran Coupe on your wish list. If so, then perhaps it ought to be. After all, just for once, the kind of car you've dreamed about may also need to be the one you really need to choose.