On all Siennas, a 266-horsepower, 3.5-liter V6 provides power through a 5-speed automatic transmission. The engine has variable valve timing for both intake and exhaust valves to help maximize torque and fuel efficiency. Fuel economy ratings for the Sienna range up to 17 mpg city, 23 mpg highway and as is the case with most minivans, the Sienna has driving manners that are very car-like, including reasonably responsive handling to complement the V6's more than ample power. All-wheel drive is available on the Sienna. It uses a center differential to split power 50/50 between the front and rear wheels under normal driving situations, but transfers more to the wheels that have traction during slippery conditions. Other Siennas are configured as front-wheel drive. The Sienna comes with a list of safety features that should lend some peace of mind. Electronic stability control and anti-lock brakes with Brake Assist are standard, as are front seat-mounted side airbags and side-curtain bags covering all three rows. AWD models also include run-flat tires, which allow the Sienna to go up to 100 miles at 55 mph once the tire loses air. Interior accommodations in the Sienna include three rows of seating and a capacity of either seven or eight. The 8-passenger configuration--offered on CE and LE trims--includes a second-row bench seat that can slide fore and aft, while other models get two captain's chairs. The "Split & Stow" third-row seat folds flat into the floor when not needed to expand cargo space. Toyota says that with the third row down and second row removed, the Sienna can fit a 4-by-8-foot sheet of plywood flat. There are plenty of places to stow stuff; in all, there are ten cup holders, four bottle holders and three power outlets. CE, LE, XLE and Limited trims for the Sienna span a very wide range of equipment, depending on whether the buyer wants simple and basic or luxurious. The base CE does include most popular equipment like keyless entry, air conditioning, power windows/locks/mirrors and a 6-speaker CD sound system; it's the only model to not offer all-wheel drive as an option. At the top of the range, the Limited adds a power moonroof, heated seats, cruise control, sunshades, a tri-zone climate control system, woodgrain trim and a parking-assist system, along with a JBL Synthesis sound system with ten speakers, satellite radio compatibility and a Bluetooth hands-free calling interface. Options at the top of the line include a DVD rear entertainment system, a navigation system that includes a backup camera, plus laser cruise control and HID headlamps--two features that aren't often seen on minivans.