MERCEDES-AMG is about to offer the most powerful E-Class saloons ever in the UK early next year.

The models chosen for the upgrade are the E 63 4MATIC+ and the E 63 S 4MATIC+.

Under the bonnet will be the new AMG 4.0-litre twin-turbo V8 engine in the E 63 S 4MATIC+ which takes peak performance to a new level at 612bhp.

Maximum torque hits a new best value of 850Nm, available over a broad engine speed range of 2,500 to 4,500rpm.

The luxury saloon will sprint from zero to 62mph is just 3.4 seconds and it will give it a top speed of 155 mph but with an AMG Driver's package it can hit 186mph.

The E 63 4MATIC+ is not quite as rapid with 571bhp to play with and this version of the E-Class can hit 62 mph in 3.5 seconds.

Mercedes claims a combined fuel consumption of 31.7mpg and CO2 emissions of 203 grams per kilometre and says the E 63 4MATIC+ and E 63 S 4MATIC+ set a new best by comparison with competitors.

Both models come with a nine-speed sports transmission specially tuned with re-engineering hardware and software.

A special model of the super-fast E-class saloon, the "Edition 1" will be available for around a year after the market launch.

It will be an exceptionally exclusive and distinctive offering with a paint finish in night black magno, dynamic stripes on the side sill panels plus new AMG 20-inch forged wheels in matt black with high-gloss polished rim flange and the Night package.

Prices have yet to be announced.