The Sienna is a big vehicle, yet it never feels overly bulky and it's never hard to handle or park. It's generally smooth, responsive and quiet, and compared to many family vehicles with comparable functional capability, it's relatively fuel efficient. An owner won't feel guilty or excessive driving it empty for errands. On long trips or school runs, loaded with people or just the driver, the Sienna is always comfortable and pleasant to drive.

With a new, more powerful engine for 2007, the Sienna moves closer to fun. This 3.5-liter V6 replaces a slightly smaller, 3.3-liter engine in all models, and it features the latest in control and materials technology, including four-cam variable valve timing (Dual VVT-I in Toyota parlance). VVT-i helps reduce emissions and deliver more power without increasing fuel consumption. In the new V6, it generates 266 horsepower and 245 lb-ft of torque. That gives Sienna class-leading power, and a few pound-feet shy of class leading torque.

We never considered previous Siennas underpowered, but the new engine makes this a hot rod among minivans. By the seat of our experienced pants, we'd say that the Toyota is now the quickest accelerating minivan you can buy, bar none, despite its hefty overall weight (more than 4500 pounds for loaded all-wheel-drive models).

Yet the hot-rod quality extends beyond acceleration. The 3.5-liter V6 is so powerful that it responds aggressively, even abruptly, to anything more than a bit of gas. A driver may jerk some heads until he or she gets a bit of practice and adjusts to the throttle response. Moreover, peak torque and particularly peak horsepower come fairly high in engine's rpm range. We wanted to keep the gas pedal floored well past respectful cruising speeds just to keep the engine pulling toward peak output and to feel maximum acceleration. The V6 remains smooth and relatively quiet all the way to the redline on the tachometer.

Gear ratios in Sienna's five-speed automatic help exploit the extra power, and the engine and transmission interact nicely. At steady speeds, the transmission keeps the engine purring at fairly low rpm. Yet if the driver floors the accelerator, the transmission immediately kicks down a gear or two, and holds that gear all the way to the redline before shifting up again smoothly and smartly. A low first gear offers quicker response off the line; the overdrive fifth gear means lower engine speeds when cruising, which translates into less engine noise and better gas mileage. It's a key reason that the 2007 Sienna gets nearly identical mileage to its less powerful predecessors (1 MPG less on the highway for all-wheel-drive models, according to the EPA), despite improved acceleration.

The same balance of smoothness and response in the engine/transmission package applies to the Sienna's ride and handling. On curving mountain roads in Southern California, the Sienna drives more like a car than a minivan or sport-utility. Its steering is responsive and there's only a 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 through tight parking lots or U-turns. That radius is tighter than most minivans.

The ride, too, is generally very comfortable, helped by a long wheelbase that limits chop, or bounce, over recurring pavement joints. On smooth pavement, few will notice any more suspension movement or roughness than one experiences in a typical sedan. On the winter-scarred tarmac that passes for roads in parts of the Mid-West, the Sienna's solid rear axle can makes its presence known by way of a skipping or slight skittishness in the rear end. We'd guess that few owners will ever drive in a fashion that lets them experience this phenomenon.

Braking is smooth and adequately short. Making bigger 16-inch wheels standard equipment allowed Toyota to design bigger brakes, and four-wheel anti-lock brakes (ABS) with electronic brake-force distribution (EBD) and Brake Assist come standard. EBD distributes the braking force to the tires with the most traction for quicker, more stable stops. Brake Assist maintains full brake pressure during emergency stopping situations, even if the driver inadvertently reduces pedal pressure in the excitement.

Toyota's Vehicle Stability Control (VSC) with Traction Control is standard on the Limited and all-wheel-drive models, and optional on other Siennas. We recommend taking whichever option package is required to get it, based on our real-world experience and a number of studies that suggest such electronic stability systems help prevent accidents. VSC senses a potential skid and uses the brakes to compensate and correct the vehicle's trajectory. Traction control helps reduce tire slippage during acceleration.

Given these features, we would recommend the Sienna's optional all-wheel-drive system to only a relative handful of buyers. The Sienna is not the type of vehicle in which all-wheel-drive delivers a truly desirable performance advantage, and the safety advantage will apply to only that relative handful, perhaps those who live in rural areas with deep snow or travel frequently on gravel roads. Even in the Snow Belt, where slush and snow can be near-daily (and generally quickly cleared) fact of winter life, the front-drive Siennas with all-season tires are generally up to the challenge. And beyond the extra up-front cost of the all-wheel drive, the system typically means at least a few miles per gallon less in real-world fuel economy.