The 2008 BMW 1 Series marked the debut of BMW's entry-level lineup to the U.S. market. Available in both coupe and convertible styles, this Series offered models including the 128i and the more potent 135i. All versions were rear-wheel drive, in keeping with BMW's longstanding tradition. The 128i packed a 3.0-liter, 230-horsepower inline-six, while the 135i was equipped with a twin-turbocharged version of the same engine producing a robust 300 horsepower. Both engines were mated to a six-speed manual transmission as standard; a six-speed automatic was optional. Inside, the vehicles offered high-quality materials, a driver-focused layout, and available features such as a navigation system, sport seats, and the iDrive infotainment system. As to safety, standard features included anti-lock disc brakes, traction and stability control, side curtain-type airbags, and front-seat side airbags.