When the sixth generation of BMW's Ferrari-baiting super sedan officially arrives in early 2018, it will do so with four-wheel drive.

Such a revelation could be met with the same sort of horror that Porsche experienced when it told the 911 faithful it was ditching air-cooled engines for water-cooled blocks.

Every M car ever built has followed the same formula -- a superb engine up front, sending 100% of its power exclusively to the rear wheels. Therefore, it's understandable that BMW is giving M5 fans plenty of advanced warning, while underlining the performance benefits the xDrive system is going to bring to the new car.

"The core component of M xDrive is a central intelligence unit with M-specific software delivering integrated control of longitudinal and lateral dynamics. The new drivetrain technology -- making its debut on the new BMW M5 -- therefore combines all of the agility and precision of standard rear-wheel drive with the supreme poise and traction of the all-wheel-drive system," explains Frank van Meel, BMW M GmbH Chairman.

Basically, the M5 is going to be the all-weather, all-road-surface super sedan but if drivers really feel they have to, they can set up the car so that it's in rear-wheel drive mode most of the time.

BMW won't yet be drawn on exactly how much power will be going to potentially all of the four wheels. All it will confirm is that the new block is a reimagining of the 4.4-liter V8 that graced the outgoing model, but it will be getting new turbochargers, higher injection pressure, new lubrication and cooling systems and an overhauled exhaust system.

All of these improvements will add up to a significant increase on the 560hp and 680Nm torque on the fifth-generation model while returning a fuel economy of 10.5 l/100 km (26.9 mpg) on the combined cycle.

Nevertheless, fans are going to be a little bit cautious about the addition of four-wheel drive, which to some, is the equivalent of putting training wheels on a road racing bicycle. Which is probably why BMW has called upon current BMW DTM works driver, former F1 racer, and self-confessed M5 fanatic, Timo Glock to offer reassurances: "With M xDrive, not only can the new BMW M5 be steered with the usual precision and agility, it also offers me something I really appreciate, living in Switzerland: a noticeable boost to traction and controllability -- even when driving in particular environmental conditions, such as wet weather and snow, and in both everyday driving situations and when pushing the car to its performance limits."