The long wheelbase, four-door Wrangler Unlimited is configurable in either Sport, Sahara and Rubicon trim with standard four-wheel drive. The standard 3.8-liter V-6 engine produces 202 horsepower, and the standard transmission is a six-speed manual with overdrive. An optional four-speed automatic with overdrive is available. Electronic stability control with roll control, traction control, brake assist and hill hold control are standard on all Wranglers. The Sahara offers body color flares, Infinity speakers, remote keyless entry, power window, security alarm and 18-inch wheels. The Rubicon features equipment that off-road enthusiasts usually add anyway, including heavy duty axles, front and rear electronic locking differentials, 32-inch BF Goodrich mud tires, sway bar disconnect system, rock rails and a heavy-duty transfer case with 4:1 low-gear ratio. The available Freedom Top three-piece modular hardtop allows panels to be removed above the driver or passenger. Other options include Dual Top Group, half doors, remote start system, front seat-mounted side air bags, and a multimedia infotainment system with 30-gigabyte hard drive and navigation system. New 2011 Jeep Wrangler Unlimited interior highlights include a redesigned instrument panel and new storage areas with improved ergonomics and upgraded materials. A redesigned center stack is easier to reach and operate. Heated, power mirrors are now available, and larger rear windows enhance visibility. All-new steering-wheel controls allow the driver to operate the radio, cruise control, hands-free phone and other vehicle functions while keeping hands on the wheel. A new 110-volt outlet is standard on Sahara and Rubicon. A body color hard top is now available. The rear wheel drive models are discontinued.