BMW have released the long-awaited technical details behind the new fifth generation M3 & M4 with the headline belonging to its engine – 424bhp @7,500 rpm plus a whopping 369 lb-ft or 500Nm of torque. In fact the new engine delivers more torque at a little over tick-over than its predecessor did at its peak.
Albert Biermann, BMW M Division’s development chief, describes this as ‘central to the new car’s performance gains’. But that’s a little misleading, because there’s more to the new M3 & M4’s performance gain than merely the magnitude of its engine output.
Take weight saving for example.
Apart from the first generation M3, each successive model has struggled with the problems of piling on a few unwelcome pounds. The outgoing E92 M3 Coupé tipped the scales at around 1,580 kg (unladen) while its predecessor the E46 M3 weighed 1,495 kg.
BMW’s goal with the fifth generation (F80/F82) car was to lose all the weight gained with the E92 and match the E46, which it has achieved. Officially the new M4 is less than 1,500 kg and more than 80 kg lighter than its predecessor.
Savings have been achieved throughout the car with a manual gearbox which is 12 kg lighter, while 5 kg has been saved from using lightweight aluminium for components such as control arms, wheel carriers and axle subframes.
The new S55 B30 engine weighs around 195kg, some 10kg lighter than the previous S65 B4 4.0-litre V8 engine.
A new five-link rear axle made from forged aluminium saves another 3 kg, while a new single-piece CFRP drive shaft saves 40 per cent over its predecessor.
The wholesale use of carbon fibre and plastics provide additional weight savings, with the M3 saloon receiving a CFRP roof for the first time and the M4 coupé gaining a boot lid constructed from CFRP and plastic, just like in the 1,385 kg E46 M3 CSL.
Despite their similar construction, BMW have said the M4 will be lighter than the new M3 saloon.
Just like the Porsche 911 and Golf GTI, BMW’s M3 has become a benchmark in its sector producing something really ‘special’ with each new generation. The new M3 & M4 are no exception.
We’ve already mentioned the top line figures – 424bhp @7,500 rpm and 369 lb-ft (500Nm) of torque. We understand the now familiar Competition Package upgrade will increase the engine’s maximum power to around 444bhp.
And while its a TwinPower Turbo unit (with two turbochargers) the engine still delivers its peak power just 800 rpm lower than the 4.0-litre normally aspirated S65 engine of its predecessor. In fact that’s higher than the 3.2-litre naturally aspirated E36 M3, which also applies the same rev limit of 7,600 rpm.
Despite appearing similar in size and format to the 3.0-litre turbocharged six used in the 1 Series M Coupé, the new S55 B30 engine is completely different. BMW M Division’s development chief, Albert Biermann, reveals that apart from the their bore and stroke measurement the engines are “worlds apart, both in their construction and induction methods.”
From a pure power-to-weight perspective the new F82 M4 is 8.3% stronger than the outgoing E92 M3, with 283bhp per tonne compared against 261bhp per tonne.
BMW say this translates into the kind of performance which is ‘noticeably quicker’, so expect 0 to 62mph acceleration in less than 4.5 seconds (currently 4.8 secs for the E92 M3) and the standing kilometre in between 21 and 22 seconds.
Despite the increase in performance, there’s an even more significant improvement in efficiency. BMW claim the new engine is more than 25 per cent more fuel efficient than before. With an average fuel consumption of 33.1mpg and CO2 emissions of less than 200 g/km, the new S55 B30 engine puts the M4 ahead of the lighter (and previous class leading) 911 Carrera S.
This improved efficiency can be seen in the engine’s specific output of 142bhp per litre. That’s 16bhp per litre more than the twin-turbocharged 4.4-litre V8 direct injection petrol engine fitted in the current M5 and M6 models, although less than the 168bhp per litre of Peugeot’s new RCZ R.
With the backlash among some buyers against the standard fitment of double-clutch (automatic) transmissions, BMW will continue to offer the M3 and M4 with a six-speed manual gearbox and the ‘option’ of the seven-speed M Double Clutch Transmission with DriveLogic for those who want something capable of mixing the conflicting values of sports performance and comfort.
The ZF-unit is significantly more compact than its predecessor and 12 kilograms lighter, using carbon friction linings in its synchroniser rings to improve upon the previously ‘notchy’ box used in the E9X M3. And while it operates more quietly than before, it also blips the throttle on downshifts – something which was previously only available on the M Double Clutch Transmission.
There are pros and cons for each option, but still a worthwhile gain for DCT aficionados – the extra gear over the manual box allows for more tightly spaced ratios and improved acceleration, especially at lower speeds where its integrated Launch Control function delivers the kind of standing-start performance which would be out of the reach of a driver using a manual box.
Chassis, steering and brakes
As you’d expect of the M3, much of its development has been conducted around that haven of driving, the Nürburgring-Nordschleife. Engineers have worked especially hard to ensure the new electronically-assisted steering feels as good as any hydraulic rack.
Three steering characteristics are available at the touch of a button on both the M3 saloon and M4 coupé – Comfort, Sport and Sport+ modes. These tie in with the optional Adaptive M suspension, which enables drivers to choose from a more relaxed and comfortable motorway setting all the way through to a more alert stiffer set-up for fast country roads and race tracks.
The rear axle subframe is now connected rigidly to the body – without the use of elastic rubber elements, leading to improved directional stability and a more adjustable chassis.
The other big news is the introduction of special M compound brakes and the availability of M carbon ceramic brakes as an option. These sit within specially developed 19-inch forged alloy wheels wearing 255/35 ZR 19 front and 275/35 ZR19 rear Michelin Pilot Super Sport tyres.
When can we buy one?
For the first time, both M3 saloon and M4 coupé will be introduced at the same time. They will debut at the 2014 Detroit Auto Show in January before going on sale a few months later. Pricing should follow the pattern set by their predecessors, with the M4 slightly more expensive than the M3 saloon which will be available for around £55,000.