Introduced in 2014 as a replacement for the 3 Series Coupe and convertible, and then gaining a four-door Gran Coupe variant in 2016, BMW's 4 series range gets a mid-cycle update as a follow-up to a pair of new engines in 2017.
The 4 Series' engines -- a 2.0L four-cylinder and 3.0L six-cylinder, both turbocharged -- are carried over from last year. The 2.0 is used in 430i models and makes 248 hp and 258 lb-ft of torque, while the 440i's straight-six is good for 320 hp and 330 lb-ft.
Mechanical updates include a firmer suspension and better roll control, and upgraded steering that BMW says provides "typical BMW steering characteristics," changes that apply to the base suspension and the M Sport and adaptive M setups.
Coupe, convertible and Gran Coupe all come standard with an eight-speed automatic transmission; a six-speed manual is a no-cost option only in the 440i coupe, which is also the only variant that starts out as a rear-driver; the xDrive AWD system is an option that can be added with either transmission.
New LED headlights are standard across the line, and the updated front end centres around a larger air intake that BMW says was intended to make the car's nose look wider and more imposing.
Out back are full-LED taillight clusters the Bavarian automaker says were likewise conceived to give the car a more distinctive look and to make the rear wheel arches stand out.
BMW adds two new colours to the 4 Series palette for 2018, called Snapper Rocks Blue Metallic and Sunset Orange. And there the 430i xDrive Sport line gets a new 19-inch bi-colour wheel design, and the optional M Sport 19-inchers are also new and can be done in a silver or bi-colour treatment.
Inside, the 4 Series also inherits the latest (sixth) generation of the iDrive infotainment system, which debuted in the 5 Series, and brings a redesigned interface that can be configured to suit the driver's wishes. An intelligent voice control system boasts what BMW calls natural language understanding; navigation system maps are updated automatically, over the air, four times a year; and the new iDrive also boasts wireless compatibility for apps.
In cars with the optional premium package, the 4 Series also gets BMW's new full digital gauge cluster that changes its appearance based on the selected drive mode.
Returning tech includes a wireless smartphone charging tray under the central armrest that boosts cell reception by linking the device to the car's external aerial, and a wifi hotspot provides in-car Internet for up to 10 devices -- in a car that realistically seats up to four.
Apple CarPlay is an option, but BMW's sweet gesture control interface hasn't migrated to the 4 Series just yet.
Prices start at $51,450 for the 430i coupe and Grand Coupe, $56,850 for the 440i coupe, and $57,550 for the 440i xDrive coupe and Grand Coupe. Convertible prices are $61,750 for the 430i xDrive and $71,050 for the 440i xDrive.