As minivans go, the Sienna is a sensible choice, but it isn't very engaging to drive. The Sienna rides comfortably and is quiet inside, but handling is lackluster. It has a lively 3.5-liter V6 but the new eight-speed automatic doesn't shift as smoothly as the previous six-speed one did. However, the transmission helped improve fuel economy from 20 to 21 mpg. The all-wheel-drive version--the only such minivan on the market--sacrifices 1 mpg. An eighth seat cleverly stores in the back when it isn't installed in place. The availability of all-wheel drive is the Sienna's biggest advantages over any other minivan. 2018 brings standard forward-collision warning and automatic emergency braking, lane-departure warning with lane-keeping assist, and adaptive cruise control.