The 2011 Tesla Roadster?s 375 volt AC induction air-cooled electric motor has an output of 248 peak horsepower (185kW) and 276 ft/lbs (375 Nm) of torque, with an EPA-estimated range of over 200 miles. The Sport trim's motor, with its hand-wound stator, produces 295 ft/lbs (400 Nm) of torque. Depending upon on how far the battery has been discharged and what source is being used to charge the batteries, the custom microprocessor-controlled lithium-ion battery (with 6,831 individual cells) can be recharged in as little as 3.5 hours. The Roadster uses a resin-bonded and riveted extruded aluminum monoquoque chassis with four-wheel independent double-wishbone suspension. Standard features include air conditioning, heated leather sport seats with lumbar support, CD/MP3 player with iPod interface, forged alloy wheels, power windows and remote keyless entry. The Sport trim features an adjustable custom-tuned suspension, forged alloy wheels and performance tires. The premium leather seats are available in nine colors or combination of colors. The available infotainment group includes satellite and HD radio, navigation, backup camera and 7 speaker Alpine sound system with subwoofer. Other options include microfiber cloth seats, Bluetooth cellular phone integration, matching body-colored carbon fiber hardtop with full headliner, metallic and premium paint, and a Mobile Connector for travel charging.Changes for the 2011 Tesla Roadster include a new front fascia and rear diffuser, improved seat comfort and internal finishes, sound dampening and a large touch screen navigation system with back-up camera. A new power control hardware enables spirited driving in exceptionally hot climates.