The Sienna is available in a wide variety of configurations; front-wheel or all-wheel drive, 2.7-liter 187-hp four-cylinder or 3.5-liter 266-hp V6 engines, and seven or eight passenger seating configurations. Both engines use a six-speed automatic transmission with manual-shift capability. Four-wheel anti-lock disc brakes with brake assist, traction control, stability control, anti-whiplash head-restraints, tire pressure monitor and full-length overhead curtain airbags are just some of the standard safety features. Available exterior features include 19-inch alloy wheels, run-flat tires, power sliding doors and a dual moonroof. The interior can be outfitted with push button start, satellite radio, USB port, dual-zone automatic climate control, power leather seats and a navigation system.The Sienna has been completely redesigned for 2011.