The fastest and most extreme BMW 1-series -- the 335-hp M coupe -- is set to go on sale across North America in May following a public debut at the Detroit Auto Show next month.
With a muscular appearance and subtly revised interior, the junior M car marks the first time a 1-series has been so badged, the German automaker said today.
More importantly, detailed information relating to its mechanical package shows the 1-series M coupe to be every bit as fast as the larger and more expensive M3 in standing-start acceleration, with a 0-to-60-mph time of just 4.7 seconds on the way to a top speed of 155 mph.
Power comes from a twin-turbocharged 3.0-liter six-cylinder paired with a close-ratio six-speed manual.
Limited supplies
The car will arrive in limited numbers this spring in North America and will be assembled alongside standard versions of the 1-series coupe in Germany.
As outlined in AutoWeek's recent drive of a prototype version of the future entry-level M car, the 1-series M coupe employs the same engine as the recently introduced Z4 sDrive35is, making it the first model from BMW's M division to boast a standard production powerplant.
In its latest guise, this engine receives a second-generation, direct-injection system together with a dual-mass flywheel, improving combustion and response.
While subtle changes to the engine's exhaust system were expected to bring about an incremental increase in power, BMW's official figures suggest it delivers the same 335 hp at 5,900 rpm and 332 lb-ft of torque at 1,500 rpm as it does in the Z4 sDrive35is.
An overboost function boosts torque for short periods of full-throttle acceleration to 369 lb-ft. By comparison, the M3's naturally aspirated 4.0-liter V8 kicks out 414 hp and 295 lb-ft. The 1-series M coupe's chassis was significantly upgraded from the standard 135i's for added response and improved levels of grip.
Lightweight materials
The front MacPherson-strut suspension gains more lightweight aluminum components while the track has been extended by 2.8 inches at 60.7 inches. The rear multilink suspension gets two additional longitudinal struts along with a host of new aluminum parts.
Hollow stabilizer bars are also employed front and rear, new bushes and ball joints are added, and the ride height is lowered 20 millimeters to give the M car a more ground-hugging stance.
The standard wheels use the same design as those offered on the M3 competition package with 19-inchers front and rear wrapped in 245/34 and 265/35 tires. As with the rear axle, the brakes are borrowed from the M3, with 14.2-inch vented and drilled steel discs up front and 13.8-inch vented and drilled steel discs at the rear, both grabbed by the M division's single-piston floating calipers.
Lower drag
The changes to the chassis have resulted in some obvious modifications to the standard 135i's body, with heavily flared wheel arches used to accommodate the wider tracks and upgraded wheel package.
The car also sports a deep new front bumper with an enlarged center air intake and air curtains (newly styled vertical ducts on the outer edges) to more smoothly channel airflow around the front wheel arches and to help reduce aerodynamic drag.
The new ducts, first revealed on the EfficientDynamics concept car, were developed in the carmaker's aero-lab wind tunnel in Munich, Germany.
Other features include unique side sills, new exterior-mirror housings together with a subtle trunk-lid spoiler and a rear bumper sporting vertical ducts that echo the look of those up front.
Inside, the upgrades are more subtle, with sport seats up front, a thick-grip, three-spoke M division steering wheel, reworked instrument graphics and a liberal covering of Alcantara.
