IT'S described as the ultimate in automotive luxury and at more than 19 feet long Bentley is about to set a new benchmark with a stretched version of its Mulsanne flagship.

The extended wheelbase Mulsanne is 10-inches longer than the regular model - and all the extra space has gone into creating an experience akin to first class air travel for those in the rear.

With extending leg rests and high-definition tablet display screens Bentley says the latest Mulsanne delivers the most relaxing automotive experience in the world.

The jumbo-sized Bentley will have its debut next week at the Geneva Motor Show alongside restyled versions of the standard car and the Mulsanne Speed.

All have a new-look nose featuring round LED headlamps and a vertical-slatted mesh grille which the company says harks back to the style of legendary Bentleys of old such as the 8 Litre of the 1930s and the R-Type Continental.

Refinements inside include a revised ‘infotainment' system centred on an eight-inch touchscreen that is hooked up to a 60GB hard drive and full Internet connectivity via 4G wi-fi.

Upholstery options now include fluted or quilted finishes with a choice from 24 different hides - and of the 400 hours it takes to hand-build a Mulsanne at Bentley's factory in Crewe, Cheshire, 150 of those are taken up creating the leather interior.

And with a likely price tag in excess of a quarter of a million pounds the new Mulsanne EWB can be fitted with the most powerful audio system currently available in any car pumping out 2,200 Watts from 20 speakers.

Further rear seat embellishments include a central console fitted out with USB ports as well as pen holders and cup holders while the car's sun roof extends to the back. For privacy, electric curtains are a standard feature.

The car is powered by Bentley's 6.75-litre V8 engine which develops 512ps giving it a 0 to 60 acceleration of 5.1 seconds and a top speed nudging 185mph with a fuel return of 19.3mpg and emissions of 342g/km.

It sits on 20-inch alloys with 21-inch rims an option and its advanced air suspension automatically adjusts ride height depending on speed.

The Mulsanne Speed, which has 21-inch wheels as standard, ups the performance ante to 537ps which results in a maximum of 190mph and shaves the 0 to 60 time down to 4.8 seconds.

The Speed also features a Mulliner specification interior which includes diamond quilted seats, a knurled gear lever and optional carbon fibre trim inserts as well external differences such as rifled exhaust pipes and dark tints in the light clusters and body trim.