The XJ comes in either regular or long-wheelbase XJL models, each available in a couple different trims. In the XJ there is the R-Sport and Supercharged, while XJL trims include Portfolio, Supercharged, and XJR575. Rear-wheel-drive is standard, though the XJ R-Sport and the Portfolio are both available with Jaguar's Instinctive All-Wheel-Drive system, which continuously monitors driving and road conditions to maximize traction and handling. Powering the XJ R-Sport and XJL Portfolio models is a supercharged 3.0L V6, which produces 340 horsepower and delivers an EPA-estimated combined fuel economy of 28 mpg. The rest of the cars in the range derive their power from a supercharged 5.0L V8. In the Supercharged trim it makes 470 horsepower, while the XJR575's tune makes an impressive 575 horsepower. Power in all XJs is put to the ground through a ZF 8-speed automatic transmission with Jaguar's sequential shift system, which adapts to driving styles and shifts at optimum engine speeds and can also be shifted manually using steering wheel-mounted paddles. Since power is available in such abundance in the XJ, so too is refinement. Depending on the trim, owners can specify up to 11 interior colors and 10 elegant veneers to taste; for leather surfaces, there are eight different colors and three grades. Attractive phosphor blue lines of light illuminate the cabin at night and a handsome analog clock with a spun-metal face sits prominently in the center of the dash. Interior amenities on the XJ include Jaguar's Smart Key System, with keyless entry and start. Integrated controls on the heated steering wheel allow drivers to access the car's impressive entertainment system, and the fully automatic, dual-zone climate control features particle and odor filtration, humidity control, and automatic window demisting. In the XJL models, the system is four-zone to allow rear occupants individual control as well. Long-wheelbase models also incorporate rear business trays in handcrafted wood veneer. Jaguar loads up the XJ with technology, intended to enhance both its driving capabilities and the experience within the cabin. JaguarDrive Control offers selectable modes for different driving conditions and moods, from slick roads where Winter Mode is required, to back roads where Dynamic Mode works with the suspension for a sportier drive. A sophisticated active differential distributes torque to the rear wheels to suit the traction and current driving dynamics. Adaptive cruise control, standard on XJR models, employs radar technology to monitor the road ahead and adjust the XJ's following distance while driving with cruise control engaged. Inside, Jaguar iTech features an interactive 10-inch HD touchscreen with navigation, virtual instruments, interactive voice controls and a media hub. A 380-watt, 14-speaker Meridian stereo system is standard, while a 1300-watt, 26-speaker surround system comes in top models. A rear-seat entertainment system allows passengers to watch DVDs or listen to music stored in the car's hard disk. Safety is paramount in the XJ, rooted in the car's aluminum and magnesium bodyshell. A bevy of airbags and active seatbelts help protect all occupants in the event of a crash, while an advanced anti-lock braking system helps drivers avoid accidents in the first place. Advanced safety technologies include a driver drowsiness monitor, active lane control with lane-departure warnings, and forward-collision warning with automatic braking.