As you'd expect, there's been an improvement in performance. The 0-62mph sprint is over in just 3.8 seconds, making it the fastest production BMW to date. That's half a second faster than the standard M4, and also marginally faster than the BMW M6 Competition pack, which manages 3.9sec. The GTS's top speed is derestricted, and stands at 190mph.
One reason for the increased acceleration is the introduction of a new water injection system for the GTS's twin-turbocharged 3.0-litre six-cylinder petrol engine. A five-litre tank with compressor in the floor of the boot is filled with distilled water, and at high revs this is injected as a fine, cooling mist. This is a first for any production BMW.
Aggressively priced supermini steps up interior game, but lacks performance...
Remapping and redevelopment of the engine has also helped BMW to achieve the power figure. Despite the power boost, combined fuel economy remains at 34mpg.
Even amateur drivers will be able to appreciate the changes, according to M4 GTS product manager Christoph Smieskol. “You feel the additional torque,” he said. “It is something you really sense in the car, especially in the higher revs, above 5500rpm. You can really feel the additional punch in the car.”
The power output is slightly less than the Mercedes-AMG C63 S Coupé’s 503bhp. However, BMW says the power-to-weight ratio was one of its main focuses and the car is lighter in several key areas.
The most notable weight loss comes from the cabin because the rear seats have been removed. Up front there are two fixed carbonfibre bucket seats, stripping out around 20kg. The Clubsport package, a no-cost extra, adds a roll-cage, fire extinguisher and racing harnesses in place of the M-striped three-point seatbelts fitted to the ‘standard’ GTS. Weight has also been saved by cutting back on noise cancelling materials and the car's door-cards.
The car features a large amount of carbonfibre, including the front bonnet and splitter, rear diffuser, roof and large, three-way-adjustable rear spoiler.
The carbonfibre-reinforced plastic bonnet saves around 3kg and the standard-fit carbon-ceramic brakes around 8kg. All the weight-saving measures enable the M4 to shed 80kg, taking the total weight to 1510kg.
The M4 GTS also comes with plenty of other upgrades, including a completely new chassis set-up and three-way manually adjustable racing coilover suspension. The car also has a sports exhaust system made of lightweight titanium.
The previous car’s ‘polarising’ orange paintwork has been eschewed, in favour of the ‘Frozen Grey’ colour, with orange highlights on the dash, wheels, front splitter and roll-cage harking back to the M3 GTS. It is also available in black or white.
The rear lights are bespoke to the M4 GTS, employing a 3D OLED system, while the headlights are adaptive LED units. Adding to the unique sporting appeal of the M4 GTS are the black-gloss grille and side grilles.
Despite the exclusive nature of the car, little in the way of personalisation is available, aside from protection glass, a £890 head-up display and internet connectivity with online entertainment.
The wheels of the GTS are unique, being forged lightweight wheels measuring 20in at the rear and 19in at the front. They are wrapped in Michelin Pilot Sport Cup 2 tyres, developed specifically for the GTS range and first used on the M3 GTS. Carbon ceramic brakes are also factory fit on the M4 GTS – a £6200 option on the standard M4.
Inside, the GTS gets an M sports steering wheel covered in Alcantara. The dashboard is also clad in Alcantara and features orange GTS badging. The door panels have fabric door pulls in BMW M colours.
A £1090 interior carbonfibre package is also unique for the UK, and adds a 12 o’clock display on the steering wheel showing g-force and lap-time readouts, switchable by wheel-mounted buttons, as well as wheel-mounted shift lights the package brings a variety of Alcantara and carbonfibre trim to the interior.
The only transmission option is the standard M4’s seven-speed M DCT dual-clutch auto, with launch control.
Just 700 examples of the £121,770 M4 GTS will be made. All have been already been allocated, with owners including collectors and racing enthusiasts. Of these, 30 will make it to the UK in right-hand-drive form.
The official UK launch of the M4 GTS is in March, and first deliveries will be next spring. Due to the high demand, BMW may source more right-hand examples, but the production total will not exceed 700.
Q&A with Christoph Smieskol, product manager for M3, M4 and M4 GTS
What do you see as the M4 GTS’s rivals?
“We see this as a rival to the Mercedes-AMG C63 Black Series, which we believe is out in 2017. The 911 GT3 is a different package. The AMG C63 S is a competitor to the base M4.”
Does it matter that you are just short of the AMG C63 S’s 503bhp?
“We always try to compete on power-to-weight, as that is where you get advantageson the track. This is a track-focused car, so that was important.”
What do customers expect from a GTS?
“These customers expect innovations. That is the case with every generation. They expect something special and they expect state-of-the-art tech on the GTS. They have a feel for the performance, and the figures are what matter to them: 0-62mph, power, the weight.”
Could you do more with the M4 in terms of power or performance?
“This is our pinnacle car. From the M4 perspective, that is it. For us, it is the demonstrator of what our engineers are capable of. We have a lot of additional lightweight components, and the OLED tail lights are a first step for us. We are seeing how they work. They have a very specific M slant on them.”
Watch the BMW M4 take on the Lexus RC F in our video below.
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