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Here’s What Makes the New M3 and M4’s M-Developed xDrive AWD System So Special

Controversial front grilles aside, the 2021 M3 and M4 are two amazing high-performance vehicles that come with plenty of exciting features. Among them is the newly developed M xDrive all-wheel-drive system, which is set to be available on the Competition variants this summer.
2021 BMW M3 and M4 Competition with M xDrive 17 photos
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The new M3 Sedan and M4 Coupe have recently arrived in dealerships and are available in two versions; for the traditionalists among us, BMW has devised RWD powertrains with six-speed manual gearboxes. Those who are hell-bent on breaking lap records can go for Competition models that are also rear-wheel driven yet offer more power and feature a lightning-fast M Steptronic automatic.

With an S58 twin-turbo straight-six that hammers out a little over 500 hp, grip is extremely important, especially through tight corners. So, the latter variants are set to also be available with AWD in a couple of months.

In charge of sending all that power to all four wheels is an upgraded, sportier version of the xDrive system developed by BMW’s M division specifically for these high-performance cars.

Traditionally, all BMWs equipped with xDrive have a rear-biased setup, and the latest M-badged system is no exception. In normal driving conditions, most of the power goes to the rear wheels, with the front ones only being fed power when conditions require it.

Drivers can choose between a default 4WD setting that dynamically controls traction while maintaining a particularly rear-focused power split at all times. Activating 4WD Sport mode directs even more torque to the rear wheels, whereas the third mode called 2WD, enabled when switching off the Dynamic Stability Control (DSC) system, will direct all the power exclusively to the rear wheels, turning the cars into veritable drifting machines.

The variable distribution of torque between the front and rear wheels is managed by an electronically controlled multi-plate clutch embedded into the transfer case. Its oil supply has been optimized to perform flawlessly even when shredding tires on the track.

To further enhance agility, directional stability, traction, and driving dynamics, the Bavarian engineers have devised a new, state-of-the-art active M-tuned differential. It ensures fully variable torque delivery to each of the rear wheels, especially when the cars are being pushed to their limits or tend to lose grip on one side because of less-than-ideal road conditions.

Power is transferred to the front and rear differentials through high-performance driveshafts specifically engineered for the two M xDrive Competition models. The output shafts that send torque to the wheels are also bespoke components developed for these cars.

The all-wheel-drive technology is also complemented by a redesigned double-joint spring strut front axle that features adapted individually tuned geometry and steering ratio settings.

A final exclusive upgrade that BMW M has equipped these two models with is a specially adapted version of the engine’s lubrication system. Unfortunately, the manufacturer hasn’t provided us with additional details about the nature of these adaptations.

Both the BMW M3 Competition Sedan and M4 Competition Coupe with M xDrive will be available to purchase in July. Like their RWD counterparts, they will only be offered with the M Steptronic automatic transmission.

 
 
 
 
 

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