Toyota stands alone in offering a four-cylinder engine in its Sienna minivan, and it's not an unreasonable choice, despite its gas-mileage numbers and the van's 4,500 pounds of curb weight.
For those on the budget, the base Sienna with its 2.7-liter four-cylinder and six-speed automatic won't feel like a penalty box. As we've observed under the Performance section, the four-cylinder Sienna's admittedly slower, but not sluggish--and it's priced well below V-6 versions. Its EPA rating of 19/24 mpg, however, is bracketed by the V-6, front-drive Sienna's 18/25-mpg rating, which means you may get slightly better mileage with the four-cylinder in mixed driving, while interstate cruisers will do better with the V-6. With either, the Sienna sits at the top of minivan fuel economy rankings, alongside the most expensive versions of the Honda Odyssey.
Opt for all-wheel drive, and the Sienna's mileage ratings fall to 17/23 mpg.