It's quick and responsive, but could be a bit quieter
The interior is top-notch and even the higher-tech controls are easy to use
Promises good Euro NCAP crash test result
Feels solid but BMW's reliability record is only average
Generally very roomy including a generous boot
Almost everything you could want comes as standard
So far, we've tried the 2.0-litre diesel (badged 420d) and the range-topping petrol (435i). Both are very swift and make overtaking feel effortless, but it's a shame the diesel sounds so gruff when you rev it - some road roar and wind noise enters the cabin at speed, too. The cars we tested were fitted with the optional Adaptive M Sport suspension which helps the 4 Series feel both agile and smooth, while its low centre of gravity and wide stance make it feel totally composed and stable on corners. The steering is both relatively light and precise - a satisfying combination. The eight-speed automatic gearbox is well worth considering as it changes gear swiftly and at just the right moment.
The 4 Series' interior is fabulous quality - the materials are extremely smart, the fit and finish are excellent and most of the switches work with a solid, positive action. Aside from minor trim changes it looks identical to a 3 Series from the driver's seat, which is great because you get the same clear instruments and BMW's intuitive iDrive infotainment system, which you navigate using a dial on the central console and simple buttons. The seats are supportive and offer a wide range of positions, but the manual adjustment that's standard on most models is fiddly and requires you to shift your weight up and down, which is quite awkward. More expensive models get electric seat controls.
It's fairly easy to get into the rear seats as the front seats tilt and slide a long way forward, creating a large gap to climb through. There's plenty of legroom in the back but six-footers will struggle for headroom. The boot is large and a useful shape.
Every 4 Series is packed with gadgets and equipment, including dual-zone climate control, cruise control, heated leather seats, front and rear parking sensors and xenon headlights; Bluetooth, a DAB radio and aux and USB sockets are also standard.
The cabin feels very solid but BMW's mechanical reliability record is reasonable rather than outstanding. Standard safety equipment includes six airbags and a sophisticated stability control system, and there are lots of high-tech safety features on the options list. The 4 Series hasn't yet been crash tested by Euro NCAP but we'd expect it to match the maximum, five-star rating of the 3 Series saloon on which it's based.
The 4 Series is around the same price as the rival Audi A5 and Mercedes E-Class coupés, but it's cheaper to run than the E-Class and than the four-wheel-drive (quattro) versions of the A5.