Adding a four door sedan to its lineup, the 2013 BMW 6 series returns with coupe and convertible trim levels. Base 640i models are powered by a 3.0-liter twin-turbocharged V6 engine that produces 315 hp and 330 lb-ft of torque. Upgrading to the 650i grants the driver a 4.4-liter twin-turbocharged V8 engine that produces 445 hp. All trims are paired to a 8-speed automatic transmission that enables an EPA estimated 19 mpg city and 30 mpg highway (for the base model). Features include xenon adaptive headlights, retractable headlight washers, 20-way power seats, leather upholstery, keyless entry, automatic climate control, tilting glass panel roof, heated drivers door lock, rear-view camera, Bluetooth® wireless capabilities, navigation system, and HD radio. Safety is comprised of advanced airbags, anti-lock braking system, electronic stability control, traction control, and tire pressure monitoring system. The 6 series is backed by a 4-year/50,000-mile warranty.