BMW is keen to point out the differences in size between the previous-generation 3 Series coupé and this 4 Series, but it makes less of a fuss about the variations between the current 3 Series and 4 Series.
Truth is, they’re not so different at all. The 4 Series is just 14mm longer, and the same amount wider, than the saloon on which it’s based, but it’s 62mm lower. Most significantly, the wheelbase is unchanged at 2810mm. It’s a set of numbers that puts the 4 Series squarely in Audi A5 territory; in fact, there’s just 2mm of length between the pair.
The mechanical layout is straight from the saloon, too, so it’s a steel monocoque and body with a smattering of aluminium and plastic to keep the weight down. BMW says the 4 Series is up to 25kg lighter than its predecessor; a 440i we tested tipped the scales at 1640kg, which is reasonable for a car of this size with the biggest of available engines. Its weight was pleasingly central, too, at 51 percent front, 49 percent rear.
The core of BMW's rear-wheel-drive 4 Series comes with the choice of six engines. The petrol options options comprise the 420i and 430i, which are both turbocharged 2.0-litre fours making 181 and 248bhp respectively, and the 440i with its 321bhp turbocharged 3.0-litre six. The latter is a particularly potent piece of kit. It offered 7bhp less power than the previous Audi S5 - although that deficit has now stretched to 28bhp - but it only has to push that oomph through its rear wheels.
Diesel choices are, unsurprisingly, likely to be more popular, but there are slightly fewer options than in the 3 Series range. It kicks off with the best seller, the 420d. With outputs of 181bhp and 124g/km of CO2 it's the model destined to be the one most frequently found on the motorways, and the one that'll find favour with company car drivers.
The remaining diesel models both share the same turbocharged six-cylinder block, but while the 430d makes 255bhp and 413lb ft, the 435d develops 309bhp and 467lb ft, making it the most accelerative model in the range.
Six-speed manual gearboxes are standard across the range; an eight-speed automatic is optional. Four-wheel drive 'xDrive' is standard on the 435d, and optional on other models.
