BMW's 2007 3 Series Coupe


SAY HELLO TO THE N54. The twin turbo inline six-cylinder (small turbos fill cylinders 1-3 and 4-6 to boost performance and cut lag), dispenses with the naturally aspirated engine's magnesium/aluminum bedplate construction (found in the 328i and all-wheel-drive 328 xi models) for an aluminum block with cast-iron cylinder liners to better handle the boost pressure. Piezo-electric injectors–adapted from BMW's diesel engines–are used to give better mixture distribution. Their quicker response lowers fuel consumption by about 3% while reducing emissions by 20%. An air-to-oil heat exchanger is mounted in the wheelwell, and dual exhaust pipes are used though–at low loads–most of the gas is exhausted through one pipe to reduce low-frequency rumble. Both manuals and automatics are of the six-speed variety.

SIMILAR, BUT DIFFERENT. The 3 Series Coupe sits on the same wheelbase as the sedan, is just over two inches longer overall, and is 1.3-in. narrower despite having the same 59.1/59.6-in. front/rear track. Up front, the steel hood is new, with strong character lines that curve from the twin kidney grille to the A-pillars. The front fenders are thermoplastic, which saves 6.6 lbs of weight, and–on average–the Coupe weighs 22 lb less than a sedan despite having more equipment. Rigidity is up 25%, and the B-pillars use an ultra-high-strength steel tubular reinforcement that is warm-molded and heat-treated while in the die. Adaptive lights that “steer” in response to steering angle, vehicle speed, and yaw rate are standard, as are cornering lights that operate at speeds up to 25 mph.

GIVING A HAND. This is the belt minder. It extends the seatbelt forward because the designers didn't want a large headrest-mounted belt loop messing up the aesthetics, or impeding rear seat access since the B-pillar is further behind the front seats on the Coupe. The arm is hidden within the rear side panels when not in use. Ambience lighting utilizes LEDs in the upper ledge of the door and rear side panels to bathe the interior in a soft red light at night, and iDrive is part of the optional navigation system.