Vehicle Overview

The rear-wheel-drive BMW 1 Series enters its fifth year on the market with a few visual changes, as well as a new higher-performance version from BMW's M division, dubbed the 1 Series M. Above the entry-level 128i is the 135i, whose compact dimensions and two-door layout give it few genuine competitors. The car comes as a coupe or convertible; shoppers might cross-shop the 135i with the Nissan 370Z, Infiniti G37 coupe or top-end versions of Detroit's muscle cars.

Exterior

With standard visual cues that come only with the 128i's optional M Sport Package, the 135i has an aggressive front bumper with three large air inlets. Xenon headlights are standard, and they carry a white bordering up top for 2012, mirroring the headlight treatment across most other BMWs. These lights include a string of LEDs embedded in the caps, a visual cue used in the automaker's redesigned 6 Series.

Rather than the 3 Series convertible's folding metal hardtop, the 135i convertible has a fabric soft-top that can open or close in 22 seconds, BMW says. It operates at speeds up to 25 mph.

The 1 Series remains a small car overall, about 2 inches shorter and narrower than a Scion tC. The popular 3 Series coupe, in comparison, measures about 10 inches longer.

Interior

The 135i's interior design is fairly traditional, with more upright shapes than sweeping contours. Dual-zone climate controls sit below the center air vents and optional navigation system, with BMW's latest-generation iDrive knob controller ahead of the center console. The system can now read text messages aloud or stream songs off a paired BlackBerry smartphone.

BMW says the cabin controls boast "a more refined look and feel" for 2012, though the layout is hard to distinguish from 2011's. In contrast to the seat belts that motor forward for easier reach in the 3 Series coupe, the 1 Series' belts are fixed onto the B-pillars.

On 135i coupes, the two-position backseat folds in a standard 60/40 split. The convertible offers only a center pass-through. Vinyl seats are standard, with leather optional. The M Sport Package adds unique headliner materials, an M-branded steering wheel and shifter, and sport seats with more aggressive side bolstering.

Under the Hood

The 135i's turbocharged inline-six makes 300 horsepower and 300 pounds-feet of torque. It works through a six-speed manual or BMW's seven-speed dual-clutch automatic. Either car hits 60 mph in about 5 seconds, BMW says. The M Sport Package adds a sport-tuned suspension with high-performance, six-piston front and two-piston rear brakes.

If that seems like too much, consider stepping down to the 230-hp, normally aspirated 128i, which is covered separately in the Cars.com Research section.

Safety

Active head restraints, two-row side curtain airbags, front airbags and side-impact airbags for the front seats are all standard. So is an electronic stability system, antilock brakes and traction control. Like most convertibles, the 135i convertible does not have the curtain airbags; pop-up roll bars deploy behind the rear seats in the event of a rollover.

1 Series M

Rather than the single-turbo setup from the 135i, the 1 Series M gets a twin-turbo six-cylinder that's good for 335 hp and 332 pounds-feet of torque. In extreme situations, the 1 Series M can enter an overboost mode to crank out 369 pounds-feet of torque (horsepower remains the same). A standard limited-slip differential can go all the way to lock, rendering maximum straight-line acceleration and better traction on slippery surfaces.

The 1 Series M comes only as a coupe, and only with a six-speed manual transmission. Citing a lower center of gravity and overall weight savings of 35 pounds, BMW will not offer the 1 Series' optional moonroof on the M car. That helps it tip the scales at just under 3,300 pounds, more than 400 pounds less than the 414-hp M3 coupe — the next rung up on BMW's M ladder. Indeed, the 1 Series M's zero-to-60 time — just 4.7 seconds, BMW says — ties a stick-shift M3's.

Visual changes include unique side mirrors that look similar to those on the M3, as well as a more aggressive front bumper and quad tailpipes. The 1 Series M's extended fenders house a track that's 2.8 inches wider up front and 1.8 inches wider in back versus the 135i. The suspension, which shares its aluminum components with the M3, supports lightweight 19-inch wheels. The car also gets cross-drilled 14.2-inch front and 13.8-inch rear brake discs.

Inside, the 1 Series M gets standard sport seats, plus gray gauges and leather-wrapped portions of the dashboard. Back to top