On curving mountain roads in Southern California, we found the Sienna drove more like a car than a minivan or sport-utility. Its steering is responsive and there's little body roll, or lean, when cornering. Transient response is good, meaning the Sienna can quickly change directions without losing composure. It feels stable at high speeds. The steering is nice and light at low speeds, and with a turning radius of less than 37 feet the Sienna is easy to maneuver in tight parking lots and in U-turns. This compares with more than 39 feet for a Dodge Grand Caravan and 40 feet for a Nissan Quest.

The Sienna accelerates relatively quickly, 0 to 60 mph in 8.3 seconds, according to Toyota, performance that's more than adequate for most traffic conditions. Toyota's 3.3-liter V6 features a two-stage variable-valve setup, called VVT-i or Variable Valve Timing with intelligence, for good torque at both low rpm and high rpm, and significantly improved fuel economy (by 3 mpg over pre-2004 models).

A smooth-shifting five-speed automatic transmission adds to the Sienna's responsiveness around town and on the highway. The five-speed automatic helps with fuel efficiency, achieving an EPA-estimated 27 mpg on the highway test. Sienna runs clean, too, clean enough for Ultra Low Emissions (ULEV II) certification. Toyota recommends premium fuel, but the Sienna will run on regular.

Braking is smooth and powerful. Making big 16-inch wheels standard equipment allowed Toyota to design bigger brakes. Four-wheel anti-lock brakes (ABS) with Electronic Brake-force Distribution (EBD) and Brake Assist come standard. ABS helps to prevent the brakes from locking during severe braking conditions. EBD distributes the braking force to the tires with the most weight on them for quicker, more stable stops. Brake Assist adds brake pressure during emergency stopping situations when the driver mistakenly reduces pedal pressure.

Vehicle Stability Control (VSC) with Traction Control (TRAC) is optional. Vehicle Stability Control utilizes the braking system to help the driver maintain control in adverse driving conditions. Traction control helps reduce tire slippage during acceleration.

All-wheel drive adds greatly to all-weather capability and recommend it for anyone who drives in wintry conditions or heavy rain. In normal driving on dry pavement, we could not discern much difference in ride quality between front- and all-wheel drive models. That's in spite of the fact that AWD models come with 17-inch run-flat tires. Run-flat tires are equipped with reinforced sidewalls with a special bead shape to permit driving for up to 100 miles at speeds up to 55 MPH even when all the air pressure is lost. We associate run-flat tires with a rougher ride quality but they're improving all the time. Run-flat tires can significantly improve safety by eliminating the need to stop to change a tire in an unsafe location. A spare tire is available for all-wheel-drive models.