The 6-Series is BMW's flagship grand tourer. The 4-door Gran Coupe is the newest addition to this line up and is actually a full four inches longer than the Coupe. Though the Gran Coupe has four doors, eating is limited to four occupants--BMW choosing to compromise the traditional fifth passenger in the name of more comfort for the other four. The cost of upgrading to the Gran Coupe is a less than $3000 making it a pretty simple choice for people who need more space but still love the styling of the 6-series.Two engine options are available in the U.S. for 2013, 6-cylinder and an 8-cylinder. The flagship 4.4L turbocharged V8 powers 650i models and makes a full 400 hp at 5,500 rpm and 450 foot-pounds of torque at just 1,750 rpm. It's paired with a paddle-shifted 8-speed automatic transmission or an optional 6-speed manual. Regardless of transmission choice, he 650i, s quick, llowing for 0-60 times in under 5 seconds. All-wheel-drive, ew for 2013 is offered exclusively on V8-engined 6-Series cars and adds about $3000 to the price of the vehicle. 640i models are powered by a turbocharged 3.0L 6-cylinder engine making 315 horsepower. Like the V8, he 6-cylinder makes most of its torque low in the rev range, full 330 foot-pounds of which are available from 1300 rpm. Despite the smaller displacement, he 640i still has respectable performance numbers, eaching 60 in a claimed 5.4 seconds. An 8-speed automatic is the only option available on the 640i.The M6 also returns, eaturing a 560-horsepower version of the 4.4L V8 that is mated to a 7-speed automatic. The M6 also comes with fuel saving technology such as auto engine stop-start and brake energy regeneration.Inside, he 6-Series gets BMW's latest technology standard, ith a 10.2-inch high-definition screen serving as the central hub for both the stereo, avigation, nd climate controls. BMW's iDrive system returns as standard equipment.Available safety features include anti-lock brakes, raction control, n anti-skid system, urtain side airbags and front side airbags. Also available are blind-spot alert, lane departure warning, full-color heads-up display, nd both rear and top view cameras. BMW's Active Roll Stabilization is available as well, hich takes on and helps cancel out body lean in tight cornering situations.The 6-Series also makes use of electronically assisted steering, hile optional Active Steering utilizes rear-wheel steering to give better maneuverability and stability at high speeds. BMW's Driving Dynamics Controller lets the driver customize steering and throttle response, he suspension, tability control action, utomatic transmission shift points and firmness at the flip of a switch. Standard features include leather interior, avigation and steering-linked headlights.