A new BMW M3 is always a special event. However, the fifth-generation model’s arrival is made more exciting because it’s being joined by the first ever M4.

To mark the occasion, here are ten key things to know about the latest M cars:

1. Two body styles are available (for now)

Buyers can choose from either the 4 Series-based M4 Coupé or the slightly more practical four-door M3 Saloon. An M4 Convertible is expected later next year, but BMW should extend the range even further. Rapid estate cars have a definite cachet, so an M3 Touring would be a great alternative to the Mercedes-Benz C 63 AMG Estate and the Audi RS 4 Avant.

The 2014 BMW M3 Saloon...

...and the 2014 BMW M4 Coupé.

Scroll down for more images.

2. The styling is subtle yet distinctive

Their redesigned bumpers, flared wheel arches, side gills, unique door mirrors and rear spoilers aren’t only there to make the M3 and M4 appear more purposeful. Rather, the bodywork changes have been introduced to help cooling, improve the aerodynamics and provide additional downforce on both axles.

On the inside, special low-set seats with extra lateral support are fitted. Those in the front are heated and electrically-adjustable.

3. Lightweight materials abound

Compared to the previous M3, mass is down by 80 kg (176 lbs) thanks to various weight-saving measures. These include the use of carbon fibre reinforced plastic for the roof panel, driveshaft, engine bay strut brace and the M4’s boot lid.

And then there are the suspension components, front wings and bonnet, all of which are made from aluminium instead of the usual steel. Even the oil sump is magnesium.

4. Power no longer comes from a V8 engine

Both the M3 and M4 feature the same 3.0 litre straight-six engine that has two intercooled mono-scroll turbochargers. Although the shift away from normal aspiration is a major break with tradition, it doesn’t come as a surprise.

It’s an effective arrangement nevertheless, because the motor produces 425 bhp (317 kW / 431 PS) with 550 Nm (405 lb/ft) of peak torque that’s available from 1,850 rpm.

5. Two transmissions are offered

The M3 and M4 come with a six-speed manual gearbox as standard, an increasing rarity in performance cars nowadays. To ensure smooth down-changes, it boasts a throttle-blipping function.

As an alternative, a seven-speed M Double Clutch Transmission (M DCT) is on the options list. Launch control is included as part of the package, plus the gear-change characteristics can be varied via the Drivelogic system.

6. Performance is better than the Mercedes-Benz C 63 AMG and Audi RS 4

The 0-62 mph (100 km/h) sprint takes 4.3 seconds, a figure that reduces to 4.1 seconds with M DCT. Regardless of the transmission type, top speed is electronically limited to 155 mph (250 km/h).

By comparison, the C 63 AMG Saloon and RS 4 Avant take 4.5 and 4.7 seconds respectively to reach 62 mph. Their top speeds are similarly restricted to 155 mph, though.

7. Efficiency is improved

Combined cycle fuel economy is 32.1 mpg (8.8 l/100km) while carbon dioxide emissions are 204 g/km. Specify M DCT and those values become 34.0 mpg (8.3 l/100km) and 194 g/km. Overall, BMW reckons the M3 and M4 are 25% greener than their predecessors.

8. There are numerous chassis upgrades

Naturally, the M3 and M4 are rear-wheel drive. To minimise wheel spin and maximise traction, an electronically-controlled Active M Differential is present that works in conjunction with the Dynamic Stability Control system.

Furthermore, the standard spec of UK market cars is enhanced by 19” forged alloy wheels and Adaptive M suspension that lets the driver select Comfort, Sport or Sport+ modes.

To match the extra performance, lightweight M Compound brakes promise better feel and less fade. If they aren’t deemed effective enough, then M Carbon ceramic replacements are a cost option.

9. UK prices have been confirmed

The M3 Saloon costs £56,175 and the M4 Coupé is £56,635 on the road.

10. Sales begin in 2014

In the UK, the first deliveries are due to take place on the 21st of June 2014.