Some will consider the announcement of the M versions of the BMW X5 and X6 arriving this fall to be heresy, a crime against the enthusiast faithful not seen since the debut of the Porsche Cayenne. Well suck it up fanboy, because the X6 M will lap the Nürburgring faster than the E46 M3. And if you really want to throw stones, blame the success of the Porsche, which demonstrated to BMW that a market exists for sporty SUVs. Both Bimmers—the powertrains are identical—put out 555 hp from a twin-turbo V-8, which is a 5-hp middle finger to the Cayenne Turbo S. The 500 lb-ft of torque in the BMWs, however, is 53 short of that of the top-level Cayenne.
The Mighty Boost
The heart of the X5/X6 M, as in all M cars, is the engine. And the heart of this engine is a trick exhaust manifold and a pair of twin-scroll turbochargers. Of course this is BMW, so there has to be an acronym: Cylinder-bank Comprehensive Manifold, or CCM. The direct-injection 4.4-liter V-8 is based on BMW’s regular production engine, adding new pistons, a new intake manifold, and revised intake cam timing. Compression has been lowered slightly, to 9.3:1 from 10.0:1. The alloy used for the cylinder heads has been altered for greater strength, the oil pan is now aluminum with integrated cooling fins, and both the intercoolers and radiator have been enlarged to deal with increased engine heat. At max boost, the Garrett turbochargers produce 21 psi of pressurized air.
An Automatic M?
The X5/X6 M will only be available with a six-speed automatic transmission similar to the one in the standard X5 and X6. (No manual! Feel free to play the heresy card again.) The M version (dubbed M Sports Automatic) works with the engine computer to cut ignition in some cylinders during a gear change to affect faster shifts. Like in other M cars that lack a clutch pedal, the X5 M and X6 M have steering-wheel-mounted paddle shifters and will hold the selected gear at the engine redline in manual mode. The SUVs also feature an economy mode that keeps the engine below 4500 rpm unless you push the gas pedal all the way to the floor. There’s also a launch-control mode, which sets the revs at 3000 for a better jump off the line and shifts automatically while at full throttle. BMW claims a 0-to-60-mph time of 4.5 seconds.
An Eminently Classy Chassis
The xDrive all-wheel-drive system is physically unchanged.
These are the first M models to use run-flat tires, with 275/40-20 Bridgestones at the front and 315/35-20 rubber at the rear. The X5/X6 M will also be the only M versions without cross-drilled rotors, a concession towards durability. Front rotors measure 15.6 inches (up 0.8 inch versus the xDrive50i’s) and 15.2 inches in the rear (up 1.6). Internals in the master cylinder have been replaced with a single-ratio valve to provide consistent brake-pedal feel throughout its entire travel.
Somewhat Sinister Styling
Distinctive gills in the front fenders and new front and rear fascias, with the characteristic quad tailpipes at the back, separate the X5/X6 M from their more plebeian counterparts, but the rest of the bodywork is unchanged. The interior changes are subtle as well, limited to a few M-themed accents and the M Drive button on the steering wheel. The X6 already looks wild enough in stock form, so the M transformation is more effective on the X5, in our opinion.
As silly as these things seem, we’re looking forward to getting some test numbers; that should prove very interesting.
The X5 M will start at $85,400 while X6 M will cost $88,900. While they are certainly expensive, both models manage to undercut key rivals such as the $90,100 Mercedes ML63 AMG and the $124,800 Porsche Cayenne Turbo S.
