The 4 Series has been a big seller for BMW ever since it was divided from the old 3 Series by a digit and some more muscular styling. An appropriate 400,000 have been sold worldwide since 2013, with half of those sales going to the four-door Gran Coupe version, and the rest divided more or less evenly between the Coupe and Convertible, both tested here.

2017 BMW 4 Series Coupe
2017 BMW 4 Series Convertible

BMW has given the range a mid-life facelift for 2017, but it’s been done with the lightest of touches and the faintest of scalpels and all but the most sharp-eyed will struggle to spot the difference, limited to minor styling and cabin tweaks, updated suspension and steering, and some new equipment and options. Will that be enough to keep the 4 fresh in the face of competition from Audi, Mercedes, and Lexus?

First impressions

If you think the 4 Series looks barely any different, you’re right — it is all but identical, and you really will have to squint to spot the new LED headlights, with their octagonal ‘circles’ and the new LED fog lamps and rear lights. The bumpers have been subtly reshaped, front and rear, and you can have a few extra splashes of chrome trim if you like.

2017 BMW 4 Series Coupe
2017 BMW 4 Series Coupe

The cabin looks and feels very familiar too — BMW says that there are new, higher-quality materials (BMW describes them as being ‘more valuable’), but again, we’re struggling to see the difference, beyond the new iDrive touchscreen with its tile-style menu layout (borrowed from the 5 and 7 Series) and the addition of the digital dial pack, also from the 5 Series. True, there are new switches that look and feel good, and quality levels are high, but it’s hard not to think that the 4 Series cabin is just a hair behind what Audi is doing with the A5, and especially so compared to the Mercedes C-Class Coupe.

2017 BMW 4 Series Coupe

Still, the basics are good — although the driving position is a little offset, you sit low down and close to the ground, to make the most of the fact that the 4 Series’ centre of gravity is a full 40mm lower than that of the 3 Series. The revised three-spoke steering wheel feels good to hold and the electronic instruments look good in Comfort mode (a little naff and video-gamey in Sport mode, but you can adjust that to taste with the iDrive).

Space in the back is good in the Coupe - not quite generous, but enough to make it a practical daily driver. The Convertible is less good, with a more upright rear seatback, and of course a roof that impinges on boot space when it’s folded away. The boot, at 445 litres, is practical enough for the class, but slightly shallow if you’re trying to load up big suitcases.  The Convertible’s boot is much more restricted — 370 litres with the roof up, just 220 litres with it down.

The new colour options of Snapper Rocks Blue and Sunset Orange look good (the blue especially) and the 4 remains engagingly muscular to look at, albeit still, to these eyes, not quite as handsome as Audi’s newer A5.

How does it drive?

Here at last, there are some differences to discuss. BMW being a company overflowing with engineers, it seems they couldn’t resist a little tinker with the mechanical parts. So, the 4 Series gets revised suspension and steering — the suspension is a little stiffer, and a little more resistant to roll, and BMW says that the extra stiffness actually trims the braking distances a touch. The DSC stability control has been updated too, as has the ABS, while the Convertible gets specially-tweaked steering to offset its higher weight and lower stiffness. BMW claims both models are more neutral when they reach their limits of grip.

2017 BMW 4 Series Coupe
2017 BMW 4 Series Convertible

The 440i Coupe, using the recently-introduced turbocharged 3.0-litre straight-six with 326hp, feels as muscular to drive as it is to look at. The engine (aided by an artificial sound generator) roars and snarls like a truly classic inline-six, and there is prodigious power on offer. It’s not an M-car, but the 440i can still add meaningful chunks of speed in very short order, and feels entertainingly old-school when it does so.

On the streaming wet Bavarian roads of our test route, the 332lb ft of torque should have been an utter liability, but the 4 Series’ balance and control really are exceptional. Even in these foul conditions you have to try, and try hard, to get the tail wagging, but for the most part it is just very composed and stable.

Impressively, the 430i Convertible feels barely any less so, which is pretty good considering the extra weight and the drop in body rigidity. The 2.0-litre turbocharged four-cylinder engine, developing 252hp, also sounds pretty good (digital assistance for that is again provided) and while it inevitably feels a touch flatter after a drive in the 440i, it’s still an eager, propulsive engine and smooth and refined in a manner that will be alien to anyone trading out of a diesel BMW. It will crack 40.4mpg, officially, too.

It’s a shame that the steering couldn’t be a touch more communicative — there’s no doubting its precision nor speed of response, but the feel at the rim is still a bit numb. That really seems to be the only dynamic deficit though. The 4 Series even rides comfortably, in spite of the run-flat tyres and stiffer suspension, although that comes with the caveat that this test was conducted on ultra-smooth German roads.

Should I buy one?

BMW says that 2,500 components are new or changed for the 4 Series, but even if you’re struggling to tell which is old and which is new, this is still an impressive, enjoyable car.

2017 BMW 4 Series Coupe

It’s definitely best savoured as a Coupe, and that big six-cylinder engine is the undoubted star of the show. The 430i, though, is possibly just a little more sensible, and yet still musters up an invigorating drive. Just make sure you spec the cabin carefully to avoid it looking and feeling too plain.

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Gallery: 2017 BMW 4 Series Facelift First Drive

BMW 4 Series

As-Tested Price £42,985 (BMW 440i Coupe)
Engine 3.0-litre straight-six turbo petrol
Output 326 hp
Speed 0-62 MPH 5.2 sec
Top Speed 155 mph
Efficiency 41.5 mpg
Transmission 8-speed auto
Cargo Volume 445 litres
Weight 1615 kg