Alpina B4 Bi-turbo revealed in Tokyo

This is the new Alpina B4 Bi-turbo - the Bavarian tuning company’s take on the BMW 4 Series coupe.

The B4 uses the same twin-turbocharged six-cylinder petrol engine and eight-speed automatic gearbox as the latest Alpina B3 Bi-turbo saloon. Unsurprisingly, power and performance figures are identical – that means 404bhp and 443lb ft of torque, with a claimed 0-62mph time of 4.2 seconds and top speed of 190mph.

If those figures are accurate, the B4 could be the quickest and fastest 4 Series available when it goes on sale next year. BMW’s own M4 coupe will be launched next year, but initial reports suggest that it won’t be quite as rapid as this Alpina.

Like the B3, the B4 gets BMW's adaptive suspension as standard, although Alpina’s engineers have tweaked the software, along with the springs and anti-roll bars.

The visual changes to the standard 4 Series coupe are familiar Alpina fare – a bespoke front splitter and new side skirts, boot spoiler, dual twin exhaust tailpipes, plus trademark 20-spoke alloy wheels.

The Alpina B4 has a more lavishly upholstered cabin, as well as blue backgrounds to the instrument clusters. As with other Alpina models, the scope for personalisation is almost limitless.

Alpina’s B3 model costs £17,065 more than a 335i M Sport saloon. Applying the same premium to the 435i M Sport suggests that the Alpina B4 Bi-turbo could start from £58,500. The car will go on sale early next year, with the first deliveries are expected in the summer.