The all-paw M3 and M4 here toward the end of 2021 are hot on the tail of a certain Tesla.

SENDING traction to all four wheels has unsurprisingly added additional spring to the step-off for BMW’s M3 and M4.

In announcing the four-wheel-drive editions are now in production, with New Zealand availability set to commence in the first quarter of this year, BMW has also signalled that both are quicker accomplishing the 0-100kmh than the rear-drive editions already flying the flag here.

The M xDrive models achieve the same 375kW/650Nm 3.0-litre twin-turbocharged 'S58' inline-six as the rear-drive Competition variants specified for New Zealand and also run a common eight-speed torque-converter automatic transmission.

Routing all the punch to all four corners, through a downsized version of the switchable M xDrive all-wheel-drive system fitted to the larger M5 super sedan, lends a four tenths’ advantage in the sprint time.

Commentators note this leaves the cars matching the next-generation Mercedes-AMG C63’s rumoured 3.5-second sprint time, and is now just two-tenths off on the all-electric Tesla Model Three Performance.

Badging aside, the M xDrive models are identical in visual appearance to the models here now and will likely deliver in identical specification, though this has yet to be confirmed.

The price is also up in the air, though obviously there will be a premium; if the pricing for the United Kingdom is an accurate barometer, the xDrive cars might cost around $6000 more than the rear-drives, which provision at $168,990 as an M3 and $172,990 as an M4.

These are the first of their family to achiev xDrive and engineering it in has demanded significant changes, more than might seem immediately apparent. For instance, these editions get a different front suspension setup, with unique geometry and even a different steering ratio. Along with that, the engine oil system has been upgraded.

At its heart is an electronically controlled multi-plate clutch to divide the engine output between the front and rear wheels. The transfer case gets a bespoke control unit and 'integrated wheel slip limitation' that is designed to be effective without requiring intervention of the stability control system.

BMW says that the M3/M4 will be rear-drive in normal conditions, though the split is fully variable. At the back, the all-wheel-drive models retain the Active M Differential of the rear-drive cars to control the torque split between the back wheels.

As standard, the system is in 4WD mode. The driver can switch to 4WD Sport for even more rear bias and, if the DSC (Dynamic Stability Control) system is switched off completely, they can choose the 2WD setting for pure rear-wheel drive. The variable traction control system, adjustable through 10 levels, can then be used, and the M Drift Analyser is fitted as standard.

The addition of all-wheel drive traction adds around 50kg to the mid-sizers' kerb weight, edging them closer to the 1800kg mark.

As per the rear-drive cars, the xDrive models have 19-inch front and 20-inch rear alloy wheels as standard, wrapped in 275/35 front and 285/30 rear performance tyres – with Michelin track-focused tyres available as an option.