Further changes have been made to the headlights, which retain the same shape as before but receive a new internal graphic similar to that seen on the 2012 Concept 4 Series, with LEDs for both low and high beam together with an optional adaptive LED function.
At the rear, the model also adopts styling tweaks to the lights and bumper, mimicking the changes to the front end.
The new BMW also receives revised 18in and 19in alloy wheels and two new exterior colours: Snapper Rocks Blue and Sunset Orange.
The changes inside are every bit as subtle as those made to the exterior. Included are a newly designed steering wheel and electroplated aluminium and chrome trim elements as well as high-gloss black panels and the choice of a number of different dashboard trim finishes, all mirroring the chances already brought to the 3 Series in 2016.
BMW has also updated the navigation system for the 4 Series, with the top-of-the-line Professional unit receiving a new interface with six tile-like icons, as seen on the latest 5 Series.
Having already received updated petrol and diesel engines as part of a running change last year, the 4 Series continues into the latter half of its planned seven-year model cycle without any significant drivetrain revisions.
Included in the new line-up is a turbocharged 2.0-litre four-cylinder petrol unit delivering 181bhp in the 420i and 248bhp in the 430i. It is accompanied by a turbocharged 3.0-litre in-line six-cylinder engine, which produces 321bhp in the 440i.
There is also a choice of three diesel engines: a turbocharged 2.0-litre four-cylinder offering 187bhp in the 420d and 221bhp in the 425d, as well as a turbocharged 3.0-litre in-line six-cylinder with 254bhp in the 430d and 309bhp in the four-wheel-drive 435d xDrive.
The 4-Series Gran Coupé can also be ordered with the turbocharged 2.0-litre four-cylinder diesel engine developing 148bhp in the 418d.
The most economical of the line-up is the 420d, which returns a claimed 70.6mpg combined, with average CO2 emissions of 106g/km.
Depending on the engine, the 4 Series can be specified with the choice of either a six-speed manual or eight-speed torque converter-equipped automatic gearbox. Selected models can also be ordered with xDrive four-wheel drive in place of standard rear-wheel drive.