The 1-Series is offered in two different two-door body styles: a coupe or soft-top-equipped convertible. Both of these body styles can be specified in 128i or 135i form. The 128i comes with a 230-horsepower, 3.0-liter in-line 6-cylinder engine, while the 135i models get a 300-hp, 3.0-liter turbocharged six.
Both of these rear-wheel drive models come with a standard 6-speed manual transmission that, in BMW tradition, provides great car control as well as a satisfying, tactile experience. Newly available on the 135i is a 7-speed dual-clutch (DCT) gearbox that enables very quick automated shifts along with improved acceleration and fuel economy. With the DCT, the 135i can now get to 60 mph in just 5.0 seconds and brings a fuel economy rating of 18 mpg city, 25 highway--the same as the standard manual transmission.
The turbocharged, direct-injected engine in the 135i has also been significantly changed for 2010. It trades the former twin-turbo setup for a single twin-scroll turbo that improves low-rev response and enables its peak torque rating of 300 lb-ft at as low as 1,200 rpm.
The 1-Series has a responsive but not overly firm ride, with a double-pivot spring and strut front suspension and rear control arms. A variable-ratio Active Steering system, which varies both the ratio and level of assist for quicker response, is optional on the 135i.
In Convertible models, the top can be raised and lowered even when moving slowly (up to 25 mph), and can go from up to fully down in just 22 seconds, and the arrangement doesn't inhibit trunk space as some retractable hard-top systems do. In either model, there's also an opening with expandable bag that allows long items like a snowboard or golf bag to fit through. The silhouette of the 1-Series convertible is much like that of the coupe when it's up. A slightly different trunklid design in convertibles helps accent the design and improve visibility. Convertible models also include a special climate-control mode that reacts to the level of sunlight, and optional Boston leather has a sun-reflective treatment that helps reduce temps on hot days. An available wind deflector helps bring a quieter, less turbulent interior at highway speeds. Whether in the coupe or convertible, there's plenty of space to sprawl in the front seats, though the back seat is quite tight.
The BMW's Dynamic Stability Control is designed to allow a little more dynamic flexibility when driving the 1-Series quickly; the higher threshold helps not only in track driving but also in snow. A special rear-brake management mode helps simulate a rear differential and get a stronger grip either out of a fast corner or in slippery conditions.
A much more aggressive look--almost like that of the larger M3--as well as a little more performance can be achieved with the M Sport Package. It brings aero upgrades, flashier wheels, sport seats, special M-branded trim pieces, and an exclusive LeMans Blue Metallic paint color, plus functional improvements that include a higher top speed, better brake cooling, a Sports Suspension, and performance tires. With the 135i, brakes are upgraded to a strong 6-piston setup in front (2-piston in back).
Entertainment options include a Harman/Kardon surround-sound system, HD radio, Sirius Satellite Radio, USB/iPod controls, while a Bluetooth hands-free interface is available. Meanwhile, a heated steering wheel is available on both models as part of a Cold Weather Package, and heated seats are available. A hard-drive-based navigation system with real-time traffic info is also available.
Adaptive xenon headlamps, which help improve vision in dark corners, are standard on the 135i and optional on the 128i. Also, LED Adaptive Brake Lights grow brighter depending on the brake force. That's in addition to plenty of standard safety equipment, including stability control, side airbags, and brake-drying and brake stand-by functions.
The M badge has always signified true performance design. For 2011, BMW finally sees fit to apply the M badge to a 1-Series model. It features an even more powerful version of the 135's 3.0L engine where it makes 335 horsepower and 332 lb-feet of torque. There's only one transmission available, a 6-speed manual. The drivetrain gets an M-exclusive variable differential lock, and there's lots more performance technology exclusive to the M. It gets its own high-performance suspension, 19-inch wheels and special computerized performance throttle mapping. The rear of the M shows off quad polished exhaust and a rear apron. Xenon headlights are standard, as are rain-sensing wipers, a 3-spoke leather-wrapped steering wheel and automatic climate control.