Detailed ahead of their public debut at November's LA motor show, both are set for a market launch commencing in April next year. A spokesperson has confirmed that the UK will only be able to order the Competition variants, priced from £110,610 for the X5 M and £113,310 for the X6 M.
They will rival the Porsche Cayenne and Cayenne Coupé in Turbo forms, and are both powered by BMW M's now familiar twin-turbocharged 4.4-litre V8. The standard X5 M and X6 M put out 592bhp, which is 25bhp more than both outgoing models. However, in keeping with the tradition set first by the latest M5, the Competition models boost this output to 616bhp. Torque is pegged at 553lb ft in all variants.
The motor in both is mated to an eight-speed automatic gearbox with all-wheel drive and an Active M differential, said to help deliver the power through the wheels over any terrain. BMW claims super-stiff engine mountings boost response and refinement, while the engine oil supply system has been designed to cope with extensive track use.
The result is a 0-62mph time quoted at 3.9sec for both cars, and a 0-124mph time of 13.7sec for the X5 M and 13.5sec for the X6 M. The Competition models drop the 0-62mph sprint down to 3.8sec, while the 0-124mph sprint is 13.4sec for the X5 M and 13.2sec for the X6 M.
All models hit the same 155mph limiter unless you spec the optional M Driver's Package, which raises the top speed to 180mph. Conversely, BMW quotes between 21.7mpg and 22.6mpg, depending on model and spec, with CO2 figures ranging from 284-296g/km.
Competition models also feature the M Sport exhaust upgrade as standard (it's optional on the regular cars), which is said to offer even greater aural thrills than the base M models' already uprated exhaust system.
This being a full-fat M model, there's also substantial chassis upgrades. Alongside the Active M differential, the xDrive all-wheel drive gives a rear-biased power delivery, with even more power shifted to the rear in the 4WD Sport drive mode. Standard-fit adaptive suspension with electronic dampers and an active roll stabilisation system are drafted in, as is Servotronic steering with a specific M tuning. The X5 M and X6 M's braking system also offers two settings for pedal feel.