BMW has unveiled the new fifth-generation BMW M3 and the production version of the M4 Coupe.  Both are due to go on sale in the UK from May 2014 with prices starting from £56,175 and £56,635 respectively.

Power comes from a new 3.0-litre straight six engine, instead of the previous M3’s V8 unit.

It’s peak power of 431hp is delivered between 5,500 and 7,300rpm, with a redline of 7,600rpm.

Peak torque, which increases by 40% over the previous model, rises to 550Nm and is available from just 1,850rpm all the way to 5,500rpm.

As standard, the new M3 and M4 are equipped with a six-speed manual gearbox.  This unit – 12kg lighter than that of the previous M3 – carries an automatic throttle-blipping feature to produce smoother down-shifts, a feature previously only available on the Double Clutch Transmission (DCT).

A seven-speed DCT unit is available as an option and as well as rapid gear changes with no interruption to the power delivery, the DCT ‘box also offers Launch Control, Stability Clutch Control to open the clutch when the car is under-steering to bring it back into line, and a series of selectable modes for more sporty or economy-minded gear changes.

The manual cars can accelerate from 0-62mph in 4.3 seconds, while the DCT-equipped models can achieve the same sprint in 4.1 seconds.  Both are electronically-limited to 155mph.

Economy has improved to 34mpg (32.1mpg for manual models) on the combined cycle, while CO2 emissions come in at 194 g/km (manual 204 g/km).

The M3 continues its established rear-wheel drive layout and uses an electronically-controlled multi-plate differential to help maintain traction.  The system, which works in conjunction with the Dynamic Stability Control, can apply 0-100% differential lock in a fraction of a second.  The DSC has been configured to allow a degree of wheel slip for easy drifting, but can be deactivated altogether.

The suspension has been redesigned with, in BMW’s words, a “painstaking attention to detail.”

The use of lightweight aluminium in the front control arms, wheel carriers and subframes saves over 5kg, while the rear five-link axle saves around 3kg.

A carbon-fibre strut brace and additional bolted strengthening joints between the subframe and the body help increase overall rigidity.

All UK cars wear 19-inch lightweight forged alloy wheels in either Ferric Grey or Jet Black.

The electric power steering adjusts the level of assistance depending on the car’s speed, and offers a choice of modes – Comfort, Sport and Sport+ – to allow the driver to select the required steering effort.

Weight-saving measures abound on the M3 and M4, such as the CFRP (carbon-fibre reinforced plastic) roof, aluminium front wings and bonnet, and CFRP driveshaft.  BMW say the extensive use of CFRP saves around 80kg in total.

Externally, the M3 and M4 wear an aggressive front apron with large air intakes, a characteristic power bulge in the bonnet, and a series of aerodynamic aids to help smooth airflow.

The BMW M3 and M4 Coupe go on sale in the UK from May 2014.