THE most powerful production BMWs ever launched are on the way to Britain in the shape of M5 and M6 models with a special competition package.

 All four variants boast a whopping 575bhp and record the fastest ever official zero to 62mph times of 4.1 seconds for the M6 Coupe and 4.2 for the M5 Saloon.

In the latter car's case there are the recent changes to the 5 Series range plus M specific enhancements like the M double-spoke kidney grille - currently seen on the M6 Coupe and Convertible - as well as the new M steering wheel with paddle shift.

As well as the extra punch, the competition package adds Sport suspension settings and steering, Sport exhaust with black chrome tailpipes and exclusive 20-inch light alloy wheels.

There's also a tuned Active M Differential for better agility round corners while the M Dynamic Mode allows for a higher threshold before the DSC kicks in.

The package comes as a £6,700 option on top of the existing standard M5 - which costs £73,505 - and is also available for an extra £6,500 on the BMW M6 Coupe and Convertible and for £5,500 on the M6 Gran Coupe.

It takes the tab for the former pair to £100,680 and £105,880 while the Gran Coupe is £103,200.

BMW has also set a new starting point for the 5 Series Saloon and Touring range with a 518d diesel engine of particular appeal to business drivers.

Powered by a 143bhp version of BMW's 2.0-litre turbodiesel, the unit offers impressive running costs with Combined fuel economy of 62.8mpg (Touring 58.9mpg) while CO2 emissions are as low as 119g/km (Touring 127g/km).

The figures mean the 518d Saloon attracts a benefit-in-kind taxation rate of 18 per cent for a car capable of 0-62mph acceleration in 9.7 seconds for the saloon and 10.1 for the estate.

Both models have also been given a sharper edge courtesy of contour lines around the grille, a re-structured lower air intake and indicator repeaters in the door mirrors.

Standard equipment has also been enhanced to include Business Navigation, Xenon headlights, BMW Emergency Call and Teleservices.

Prices start at £29,830 for the 518d SE Saloon rising to £32,630 for an M Sport derivative. Touring models are from £32,155 for the SE rising to £35,080 for an M Sport.