- Aggressive, track-inspired looks
- Potent twin-turbo six-cylinder engine
- Advanced chassis controls
- Ligther weight than predecessor
- The benchmark is back
- Gas mileage is meh
- Still quite expensive, without remorse
- Lighter than before, but still not light
- No more V-8 wail
Minus the V-8 and almost a couple hundred pounds, the 2015 BMW M3 is the best performer yet to wear the vaunted badge.
The 2015 BMW M3 is both a yardstick and a target, considerably different from its predecessors, but with a clear heritage of performance. An aggressive face leads the way for the new turbocharged six-cylinder engine and lighter chassis—and some astonishing performance.
From the outside, the M3 doesn't veer dramatically from the 3-Series formula. There's a power bump on the hood that suggests the muscular power underhood, and the nose, sides, and tail get some track-bred cues to go with the flared fenders and low-profile tires. There's even a carbon-fiber roof option, for the first time on the M3 sedan. Inside, the 3-Series shapes are even more clear, with M badges, upgraded sport seats, M-specific controls for the electronics, and racier-looking carbon fiber trim add to the high-performance look and feel of the cockpit.
- Read Motor Authority's BMW M3 and M4 first drive
- Our 2015 BMW M4 review
- Our 2015 BMW 3-Series review
- Our 2015 BMW 4-Series review
So what are the key stats on the industry's long-time benchmark sport luxury sedan? Power is up from the previous 4.0-liter V-8's 414 horsepower to a stout 425 horsepower courtesy of a 3.0-liter twin-turbo in-line six-cylinder. Unlike many turbo engines, this one revs to 7,600 rpm, and carries its peak output from 5,500 rpm to 7,300 rpm. Peak torque for the new engine is 406 pound-feet, available from 1,800 rpm to 5,500 rpm. The myriad changes to the in-line six earn it a new name (S55) and of course, those hugely upgraded power ratings, but the S55 also has a droning, artificially generated engine noise that really underserves the classic BMW in-line six sound.
Together with a new electronically controlled limited-slip differential and the M-DCT seven-speed dual-clutch transmission, the 2015 BMW M3 hits 60 mph in about 3.9 seconds, according to BMW. Top speed is electronically limited to 155 mph. Should you opt for the six-speed manual transmission, the 0-60 mph time will rise to about 4.1 seconds. Either way, the M3 is a puller of the top rank; it's really, really tough to catch it napping off-boost, and BMW's new Active M Differential system helps maximize the impact of the power by electronic oversight. It adjusts its locking percentage between the rear wheels from 0-100 within milliseconds, it is tuned to maximize grip and traction, aiding the car's ability to rotate in response to the driver's inputs.
BMW has lightened up the M3's chassis as well. With aluminum hood and fenders and carbon-fiber reinforced-plastic bits, the end result is a car that's about 176 pounds lighter than the previous M3, at just under 3,300 pounds. Extensive use of aluminum, including in the front fenders and hood, as well as carbon fiber in the trunk lid, driveshaft, and roof, help save the weight and keep what weight remains lower and more toward the center of the car for further improvements to handling and balance.
The suspension is also largely new for the 2015 M3, with a double-join sprung front axle using lightweight components including aluminum control arms, wheel carriers, and axle subframes for a savings of 11 pounds. At the rear, a five-link setup uses forged aluminum control arms, shaving about 6.6 pounds from the unsprung mass.
An Adaptive M suspension system is also available, adding Comfort, Sport, and Sport+ modes, made possible by variable-rate dampers. The same three mode settings also control the electric power steering in all M3s, raising or lowering the steering force and feedback to suit the mission.
Even the body has been optimized for performance, with advanced aerodynamic work done to ensure both minimal drag and maximal cooling and lower levels of lift--hence the Gurney lip spoiler at the rear, the gills up front, and the sculpted side mirrors. All work together to balance these challenges in airflow management.
The result is a car that loves quaffing long uphill runs at the horizon with gusto, shaving off a hundred miles per hour undramatically with the carbon-ceramics, settling firmly and predictably into uphill 30-degree bends without a knee bent. It's so close in performance delivery to the related M4 coupe, the two are almost indistinguishable on the track, other than the view outward and the extra padded leather seat. BMW says there's almost no difference in the cars' center of gravity and weight distribution.
It's tough to call this M a sports car, but few grand tourers come closer to touring-car grip and balance. It's not without its faults, though. The steering works so well on tracks with big, wide, sweepers, it's hard to reconcile with the lack of communication when it's drilled through tighter curves. The throttle response and shifting are rapid-fire-quick in Sport+ mode--avoid it on the street. And while fuel economy is better, the M3's highway figures still pale behind those of even true sports cars like the Corvette or Porsche 911.
Prices for the M3 begin at $62,950. Some of the most comprehensive safety features ever are fitted this variant of BMW's core model--but a rearview camera is unconscionably an option inside a $4,000 package that bundles a head-up display with special M functions, parking sensors, rear heated seats and steering wheel, and satellite radio. A $1,900 package includes blind-spot monitoring, lane-departure warning, and active braking, and for weekend track stars, the $8,125 charge for carbon-ceramic brakes might actually seem worthwhile. The dual-clutch transmission is $2,900; the adaptive suspension, $1,000.