BMW GB easily exceeded its sales expectations last year with 6-series and managed to secure extra units after orders surpassed the original 1,800.

That was with the 645i; now with the new 630i, BMW hopes to more than double UK volumes. Featuring the all-new 3.0-litre 258bhp engine, the 630i drops the 6-series entry price by around £5,000, starting at £45,255 for the coupe and £50,655 for the convertible. Lower running costs should appeal to a slighter younger and more mixed customer base than the 645i, bought mainly by 45-55-year-old businessmen.

BMW claims the engine is the lightest six-cylinder – at 121kg – on the road thanks to a block composed from magnesium and aluminium rather than cast-iron.

It’s also the first time BMW’s Vanos (which controls inlet/outlet valve timing) and Valvetronic (which controls by how much the valves open) have been fitted to a six-cylinder and the result is a smooth, more responsive engine.

Power is up 27bhp over the 3.0-litre unit used in other BMWs, while torque is delivered across a wider range: 270Nm at 1,500rpm with the 300Nm peak from 2,500 until 4,000rpm. The redline has been raised 500 notches to 7,000rpm. That means quicker pick-up at low speeds, more consistent power delivery when accelerating, and crisp mid-range performance.

Driven hard it sweeps to 62mph in 6.5sec, and dropping a gear catapults the car for safe overtaking, accompanied by a throaty roar.

And there’s no sacrifice in efficiency: 31.4mpg for the coupe and CO2 emissions a tax pleasing 216g/km.

Retailers should look to sell 2,000 630i models this year, roughly split 1,200 coupe and 800 convertible. They can also expect to see the 3.0-litre engine added to the 5- and 3-series shortly.

Strength: Class-leading performance plus efficiency
Weakness: Not that much cheaper than the 645i
Opportunity: More sales for the relentless BMW brand
Threat: New Jaguar KX8 due later this year
The USP: First sight of BMW’s next generation lightweight 3.0-litre
Price: £45,255 coupe; £50,655 convertible
Engine: 3.0-litre 258bhp, 221lb-ft
Transmission: 6sp man/auto/seq
Performance: 0-62mph 6.5 coupe; 6.9 convertible; top speed 155mph
Efficiency: 31.4/29.7mpg comb; 216/229g/km CO2
CAP RV (3/30k): 49-50%
Rivals: Jaguar XK8, Maserati Coupe GT