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2015 BMW M3 & M4 - First Drive

Out with the V8, in with a turbo-six

Greg Emmerson
Jun 25, 2014 SHARE

2015 BMW M4 & M3 Details:

  • First-ever turbocharged M3 engine | New M4 model | Widebody styling
  • S55B30T0 3.0L i-6 biturbo engine | Single-scroll turbos | One-piece, carbon fiber driveshaft
  • 425hp, 406 lb-ft | 0-60mph in 3.9sec (M-DCT) | 3540 lb (6MT) - lighter than predecessor
  • 6-speed manual or 7-speed M-DCT | Improved economy | Priced from $62925

Electronics: M preset button | BMW Apps | Connected Drive | Augmented engine noise | Active suspension and diff

+ Pros: Awesome driver's car | Sedan practicality or Coupe looks | Improved economy and lightweight | Massive torque | Manual and composite brakes option | Sounds great

- Cons: Can't really think of any...


2015 BMW m3 m4 06 Photo 2/127   |   2015 BMW M3 M4 06

Entering its fifth generation, few cars carry the weight of expectation like a new BMW M3. Perhaps Porsche's engineers feel the same responsibility, but they're playing in more rarified air. The cost of a 911 means its developers have bigger margins, but a BMW must be practical, versatile and affordable. And for a new M3, it must also be damn fast: able to compete with the 911 on a racetrack.

Bimmerfest 2014 - Pasadena, CA

This year, we're also seeing the birth of a new vehicle, the BMW M4. It could potentially steal the M3's crown with the stylistic advantage of its sleek coupe body. However, Albert Biermann, head of development for BMW M explained that the team went to extraordinary lengths to ensure both cars were virtually identical mechanically and dynamically. "The M3 is an icon," he explained. "We couldn't have it upstaged by the BMW M4!"

So while the BMW 435i has several key advantages over the 335i, you'd be hard pressed to detect the differences once the "M" badge is applied. During two days of hard driving, which included a section of Portuguese road used by the World Rally Championship, and laps of the sublime Autodromo Internacional Algarve in Portimao, we didn't discern any major differences.

2015 BMW m4 driver side front view 05 Photo 6/127   |   2015 BMW M3 & M4 - First Drive

The engineers admit the BMW M4 is about 50 lb lighter (US regulations might show a different weight because they must account for popular optional extras) and had miniscule differences in setup - it's slightly lower, has a different weight distribution and center of gravity - but we're only talking about single percentage points.

Some drivers seemed to pick a favorite but the differences are more stylistic. Do you like your toys to have two doors or four? Do you prefer the F80 M3's fender flares, or the F82 M4's cleaner lines?

We're traditionalists. So we'd take the M3. We like the badge and the greater practicality, but concede we felt the M4 drove slightly better, although it's entirely subjective.

What we should be worrying about is how the cars drive. Do they deserve the pedigree the badge commands? To be honest, we were slightly concerned during our first spell behind the wheel...

2015 BMW m3 driver side front view 07 Photo 10/127   |   2015 BMW M3 Driver Side Front View 07

2015 BMW M4 Convertible Announced

The two M presets on the steering wheel had been programmed by our hosts with different settings - M1 was more of a comfort program, while M2 was more racy. We were advised to start in M1 and explore some real roads.

On the freeway, the M3 and M4 are hooligans. Both tickle along at 100mph as if it were 55. Pull the paddle two, maybe three times, and you can unleash the sort of accelerative force usually preserved for supercars.

2015 BMW m3 driver side rear quarter view 02 Photo 11/127   |   2015 BMW M3 & M4 - First Drive

With 0-60mph conservatively quoted at 3.9sec using the M-DCT transmission (4.1sec for the 6MT), there's a surge of acceleration that barely retards in the higher gears. We nudged up to 145mph and found it as eager to continue as it was at 80mph.

Hard acceleration is accompanied by a deep, bassy bellow that initially puts you in mind of the outgoing 4.0L V8, although the new S55 engine only revs to 7600rpm - lower than the V8's 8400 but still high for a turbo-six.

While engine power is similar to the V8, what really differentiates the engines is the S55's abundance of torque. Where the V8 had 295 lb-ft at 3900rpm, the F8X has 406 lb-ft from 1850 to 5500rpm. So while the V8 had to be kept in its sweet-spot at high RPM, the S55 has a different character. You don't need to be as busy with the paddles, which should also suit the manual transmission. And while the M-DCT might be quicker to 60mph and easier to drive on-track, those of us who appreciate and desire greater control were delighted to learn you can still get a manual transmission, cementing the BMW M4 and M3's status as a true driver's car.

2015 BMW m3 passenger side front view 03 Photo 15/127   |   2015 BMW M3 & M4 - First Drive

There were rumors that the F8X models might not get a manual, especially since most of its competitors have eradicated them. However, BMW expects 20% of its sales to be 6MT. Perversely, most of them will be sold in the US, the country that's otherwise helping to banish the stick-shift, but when it comes to our sports sedans, we still want a third pedal!

The gearbox was taken from the BMW 1M, which in turn came from the 135i. For this application it was modified internally for strength, gaining carbon-coated synchromesh. They also removed 26 lb, making it 66 lb lighter than the M-DCT.

When using the 6MT, the software provides rev-matching blips on down changes, unless the driver selects Sport Plus. At this point, it's up to him to execute heel-and-toe downshifts.

The original aim of the development team was to get the car under 3500 lb and they came impressively close. A manual transmission and carbon-ceramic brakes will get you to within a few pounds. If it wasn't for the latter's six-piston calipers and the fact it needs larger 19" wheels, they might have succeeded.

2015 BMW m4 passenger side view 19 Photo 19/127   |   2015 BMW M4 Passenger Side View 19

This is the first time a new M3 has been lighter than its predecessor, which is a big deal. Weight is the biggest enemy of acceleration, braking, handling and economy, so reversing the trend should pay dividends for owners.

Other weight-saving technologies include the electromechanical power steering, which saved 8 lb compared to the previous M3. Then there is the aluminum front subframe that's 9 lb lighter than on the 435i and gains extra bracing. The hood is 17.5 lb lighter than the E9X, the fenders saved 8 lb and the carbon-reinforced plastic trunk on the BMW M4 is 11 lb lighter than the 435i - the M3 retains its steel trunk but the M4 required the new part because the coupe is inherently less aerodynamic. As a result, it has a molded spoiler similar to the E46 M3 CSL. This equalized the downforce between the two cars, with the carbon lip on the M3's trunk more of a cosmetic addition than a high-speed requirement.

Although we don't have a figure, the S55B30T0 engine is lighter than the similar N55 3.0L in the 435i. In this application, the steel cylinder liners are replaced with an iron coating sprayed onto the bores. This is then machined to create a very thin friction layer that protects the pistons.

There's also a new crankshaft that's 30% stiffer than the N55 and 4.5 lb lighter. It will inevitably be one of many parts that 335i and 435i owners will eye jealously for their own cars...

2015 BMW m4 rear view 22 Photo 23/127   |   2015 BMW M4 Rear View 22

The engine has been fitted with what BMW calls its third-generation turbochargers. Two single-scroll units were designed to work with the 7600rpm rev limit, forming part of the company's new high-revving turbo engine philosophy. They don't see why a turbo motor must have a narrow powerband, although getting turbos that are small enough to be lag-free, yet able to provide so much power up to the rev limit is quite an achievement.

The power supply should be consistent because a great deal of effort went into engine cooling. It uses a water-cooled intercooler and has five radiators behind the front bumper to control operating temperatures.

A new exhaust system was designed that not only saves weight but also uses a flap system to essentially bypass the rear muffler. Whether this gains power is unlikely with four catalytic converters upstream (the important ones are nearest the engine, with two additional cats under the car, required by US law, although there was a suggestion a new car could run without them for several years and still comply with most emissions regulations...).

The exhaust flaps open when certain criteria are met for throttle position, engine speed and load. At this point, the sound takes a nasty turn, gaining significant bass and menace. It might put a few exhaust makers out of business because it sounds that good. At speed on the fast straight at Portimao, you wouldn't imagine it could be improved.

Unfortunately, BMW shot itself in the foot again by using augmented noise in the cabin to enhance the engine note at low speed and light loads. Their argument is that an enthusiast wants to know what the engine is doing at all times, and generating an artificial sound through a noise generator will assist the driver.

2015 BMW m3 driver side rear view 10 Photo 45/127   |   2015 BMW M3 Driver Side Rear View 10

The problem is that when an enthusiast learns that the sound is augmented, you tend to assume it's because the mechanical noise is insufficient or unappealing. As we said, this is far from the truth - the turbo-six sounds amazing - and the augmentation does give feedback at lower speeds. It's simply the perception that this shouldn't be necessary that undermines what amounts to good execution of a relatively new concept.

Significant weight savings came from the one-piece carbon fiber driveshaft between the transmission and modified M5/M6 active differential (it has different gearing and long fins to avoid a separate cooler). The previous car had a two-piece steel shaft to avoid harmonic resonance but the carbon item has a higher resonant frequency, avoiding the problem. And while this technology isn't new, Albert Biermann explained that it was how the carbon shaft was attached to its steel joints that made the piece revolutionary.

Back to our driving impressions, and the M3 initially disappointed because the steering was set in Comfort and the throttle in Sport mode. The car felt lazy in the corners, not wanting to turn-in willingly or respond quickly to pedal inputs. Even the brakes felt rather numb with their carbon-ceramic rotors.

2015 BMW m4 passenger side view 20 Photo 46/127   |   2015 BMW M4 Passenger Side View 20

Fortunately, the M2 button rectified the situation. It had Sport steering and Sport Plus throttle activation, bringing the car alive. We soon clicked the steering into Sport Plus with the console button to provide the weight and response we wanted. And while all electric steering lacked real feedback, it did everything else almost perfectly.

We should point out that the steering helped disguise the tramlining that would otherwise occur with the wide 255/40 front tires fitted to the cars.

Perhaps our only complaint was the suspension. The roads weren't potholed but the surface was far from flat. We found that the Sport and Sport Plus settings created too much bounce caused by what felt like insufficient suspension travel and stiff springs. Even with the optional Adaptive M suspension, the electronic dampers tried to adapt but the car continued to bounce, affecting traction and confidence.

2015 BMW m3 driver side front view 08 Photo 47/127   |   2015 BMW M3 Driver Side Front View 08

In this situation, we found the roads were best suited to the Comfort setting, which was far from its sportiest, yet the EDC was able to compensate sufficiently. This removed the bounciness, restoring control, although we did have to contend with a degree of high-speed float.

The Sport and Sport Plus settings were utilized on the racetrack, where the dampers didn't need to absorb major irregularities. On the smooth surface, the car felt taut and controlled, its ideal weight distribution (51.6/48.4% M3, 51.8/48.2% M4 6MT) giving it perfect balance in the turns, with the handling remaining almost neutral unless you entered a turn too fast, after which there was understeer to gather you up. And, of course, you could induce power oversteer on the exit, although the M Dynamic Mode on the traction control would gently bring the tail into line and allow you to maintain phenomenal forward progress. The Active M differential also played a large part in ensuring the power went to the tire with the most grip.

The carbon brakes really shone on the track. They were welcomed on the road but the inability to induce fade meant you could maintain consistently fast laps, braking deeper and deeper as confidence grew. We found we could accelerate well past the braking markers without ever getting into trouble.

2015 BMW m4 rear view 21 Photo 48/127   |   2015 BMW M4 Rear View 21

The huge front grip from the wide Michelin Pilot Super Sport tires was greatly appreciated. They followed exactly where you pointed them with the utterly precise steering. On occasion, you'd find yourself sawing to find the maximum grip, only to discover you had it - the car was doing exactly what it should without needing to be coaxed.

Exiting a corner, we found ourselves able to run a gear higher than expected. This was thanks to the torque reserve that would slingshot you towards the next apex.

It was a magnificent experience to drive the M3 and M4 so hard on both the road and track and find no real faults. Sure, the suspension was rather stiff on some road surfaces but it has three settings to cure the problem. The steering could also be rather pedestrian until you again selected the best setting. And while button pressing was required to find the right combination, the reward was an awesome setup once you got it right.

While it's relatively heavy and certainly a large car, the performance potential of the F8X BMW M3 and M4 is a notch above anything that's gone before it. I fear we may regard the E9X as a rather unwieldy tool once we have the chance compare both generations on the track.

2015 BMW m3 carbon fiber roof 13 Photo 49/127   |   2015 BMW M3 Carbon Fiber Roof 13

Perhaps our only other observation was that the M3/M4 only come alive when driven hard. At regular speeds they felt more pedestrian, but most drivers will always be looking for any opportunity to unleash these beasts.

Our final thumbs up was for the multi-adjustable, plastic-backed sports seats that provided incredible support in the very fast turns at Portimao. Their only snag is the poorly positioned latch that makes entry into the M4's rear seats more difficult than it should be, but it's something you'll acclimate to.

Another factor to consider is fuel economy. The European figures suggest a combined figure of 26mpg, with up to 34mpg on the freeway, which would have been impossible with the V8. That will help reduce the running costs, although the purchase price is higher - the M3 starts at $62925, while the M4 is $65125 and the Convertible will be $73425 (including destination and handling).

As for optional extras, the carbon brakes are $8150 extra, M-DCT is $2900, adaptive suspension is $1000 and 19" wheels are $1200. However, there's a long list of standard equipment to keep most drivers happy if you can only afford a base model. The cars go on sale this summer.

Tech Spec
2015 BMW M3

Layout
front-engine, RWD

Engine
2979cc S55B30T0 inline six-cylinder 24v with two single-scroll turbos, Vanos, Valvetronic, direct injection

Drivetrain
six-speed manual or seven-speed M-DCT automatic transmission, Active M differential

2015 BMW m3 passenger side front view 04 Photo 53/127   |   2015 BMW M3 & M4 - First Drive

Brakes
four-piston BMW/Brembo fixed calipers, 15" rotors f, two-piston, 14.6" r (optional six-piston BMW/Brembo fixed calipers, carbon-ceramic 15.75" rotors f, two-piston, 15" r)

Suspension
aluminum double-joint strut-type f, five-link axle r

Wheels & Tires
18x9" f, 18x10" r wheels, 255/40 R18 f, 275/30 R40 r tires (optional 19" wheels required for composite brakes)

Performance

Max power
425hp at 5500-7300rpm

Max torque
406 lb-ft at 1850-5500rpm

0-60mph
3.9sec (DCT, 4.1sec 6MT)

Top Speed
155mph (limited)

2015 BMW m3 front view 09 Photo 54/127   |   2015 BMW M3 Front View 09

Weight
3540 lb (6MT)

Economy
TBA

MSRP
$62925 (inc D&H)

2015 BMW m3 m badge 12 Photo 55/127   |   2015 BMW M3 M Badge 12
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By Greg Emmerson
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