PORSCHE is raising the bar for performance and efficiency with its new generation 911 sports car - courtesy of turbo power.

The new 911 Carrera and Carrera S stablemates are expected to arrive in the UK during December.

And for the first time their rear-mounted flat-six engine will come with twin turbocharging as well as a more advanced chassis and a new Porsche communication management set-up.

The German marque is pricing the pair at £76,412 for the Carrera coupe and £85,857 for the S equivalent while the cabriolet will cost £85,253 for the Carrera and £94,698 for the S.

In the Carrera coupe, the 3.0-litre engine develops a hefty 370bhp and with the brand's PDK transmission and Sport Chrono Package can scorch from 0-62 mph in 4.2 seconds, making it two tenths of a second faster than its predecessor.

In the case of the Carrera S there's 420bhp of wallop and the acceleration benchmark can be reached in just 3.9 seconds, meaning it is the first 911 in the Carrera family to undercut the four second mark.

The top speeds of both models have also increased further, the 911 Carrera now boasting a top speed of 183mph - an increase of 4mph - while the S now has the potential for 191mph, up by 3mph.

Depending on model, the 911 is also now almost 12 per cent more efficient as the Carrera with PDK can return a Combined 38.2mpg - an increase of 3.8mpg - while the Carrera S consumes 36.7, an increase of 4.2mpg.

A new option of rear-axle steering, available on the Carrera S models for the first time, further extends the Porsche's dynamics, to the point that the car's fastest lap time around the North Loop of the Nürburgring circuit is reduced to 7 minutes, 30 seconds - ten seconds faster than before.

The newcomers also herald some fresh design features, like new headlights with four-point daytime running lights, handles inset to the door panel without recess covers plus a redesigned engine lid with vertical louvres and new tail lights.

Inside, the new Porsche Communication Management with an enhanced multi-touch display console offers more functions and simpler operation.

Standard kit on every 911 Carrera includes leather interior, sports seats, PCM including sat-nav with seven-inch touchscreen, auto climate control, Sport button, Bi-Xenon headlights and Porsche Active Suspension Management.