Channeling the prodigious reserves is an eight speed automatic gearbox featuring stop/start and brake energy recuperation functions. It replaces the earlier six-speed unit used by the earlier X5 M and X6 M and is allied to a permanent multi-plate clutch four-wheel drive system.
The system is capable of apportioning up to 100 per cent of drive to either the front or rear axle and features electronically controlled torque vectoring as part of a so-called Dynamic Drive package.
Tipping the scales 30kg under their predecessors at 2275kg and 2265kg respectively, the new X5 M and X6 M possess a claimed 0-62mph time that has improved by 0.3sec on the first-generation models, at 4.2sec. The nominal top speed remains limited to 155mph, although owners can choose to have it raised to 174mph.
By comparison, the 2185kg Cayenne Turbo possesses claimed figures of 4.2sec and 174mph, while the 2345kg ML63 AMG has performance claims of 4.8sec and a limited top speed of 155mph.
BMW puts the combined cycle consumption and average CO2 emissions for both of its new M division SUVs at 25.5mpg and 258g/km. This represents a 5.2mpg and 67g/km improvement on the old X5 M and X6 M.
Distinguishing the new models from less powerful versions of the third-generation X5 and second-generation X6 is a new front bumper with large air intakes for added cooling, painted wheel arch flares, revised front fenders with a stylized air duct to extract air from the front wheel houses, chunkier door sills and a deeper rear bumper with four chromed tailpipes.
Buyers can choose between standard 20-inch wheels – 10 inches wide up front and 11.5 inches wide at the rear, shod with 285/40 and substantial 325/35 tyres – or optional 21-inch rims.
BMW’s M division says it brought significant changes to the standard X5 and X6 suspension systems in the creation of the X5 M and X6 M.
Among them is a modified upper front wishbone allowing increased camber, more controlled camber progression as lateral forces rise and an increased steering pivot axis. Further changes include unique elasto-kinematic properties with firmer springs and dampers that provide a 10mm reduction in ride height over standard models.
The new M-car duo come with standard air suspension featuring a self-levelling rear axle and electronically adjustable dampers in three modes: comfort, sport and sport plus, along with active roll bar stabilisation and an electronic stability control system featuring three different modes.
In testing at the demanding Nürburgring, prototypes of the X5 M and X6 M are claimed to have achieved lateral acceleration values of up to 1.2g during cornering.
Prices for the X5 M and X6 M start at £90,179 and £93,070 respectively. Both cars will also receive their European debuts at the Geneva motor show next March.
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