No fewer than 13 trim levels and six engines ranging from 1.4-2.8 litres allow one of Britain’s best-selling business cars to provide a bewildering plethora of choice for the customer.

But the ambition to create another new niche product in the upper-medium segment has prompted Vauxhall to add even more showroom permutations to its line-up of Insignia saloons and Sport Tourers.

With a twin turbocharger unit bolted on to its 2.0-litre diesel motor, the fleet-favourite model gets the twin benefits of an urge and greater pull to help drive the company’s next assault on the premium sector.

Vauxhall doesn’t expect the most powerful diesel Insignia so far to sell in big numbers, but it is confident the flagship BiTurbo variants – 10 in total – add emphasis to the aim to win the manufacturer a more upmarket image.

“In a way, the recession has worked well for us by prompting fleet managers to give closer scrutiny to the cost of premium motoring,” said a spokesman.

“Insignia was well received because it was light years ahead of the Vectra in style and technology.

This has made it a regular top 10 best seller and we think twin-sequential turbocharging will further extend the appeal of the car.

“Even though it is unlikely to account for more than 2% of registrations, the BiTurbo should create interest as it is one of the few cars in its class with the option of four-wheel drive.”

Carrying a premium of £1,800, the new halo car has an extra 34bhp and 37lb-ft more torque than the most powerful single turbo Insignia and comes in SRi, SRi VX-line and Elite trim levels. It has bold 18-inch alloy wheels, lowered and uprated suspension and prominent dual branch exhaust tailpipes and is as potent as it appears out on the road.

With the thrust of a six-cylinder motor, a lack of turbo lag allows the power to flow without interruption for rapid acceleration and easy overtaking.

Significantly, an adaptive damping system that changes settings and costs £790 extra on other models, is fitted as standard and firms up the ride to help sharpen handling during enthusiastic progress.

In more restrained driving, the BiTurbo behaves much like lesser-powered versions with a compliant ride and low noise levels, while start-stop technology and a gearchange prompt indicator help operating economy.

Like the standard SRi, the BiTurbo has a comprehensive spread of standard equipment which includes climate control, cruise control, a powered driver’s seat with lumbar adjustment, a leather-covered sports steering wheel, automatic lights, a 60-40-split rear seat and fog lights.

By Maurice Glover