Similar specs, subtle differences
The specifications of these four vehicles would lead you to believe that the minivan segment has been commoditized, at least in a mechanical sense. Each van's V-6 engine makes about 260 hp, and power is sent to the front wheels through an automatic transmission. The front suspension is a pair of MacPherson struts, and the rear typically uses a multilink setup. Despite the similarities, though, each van has distinct attributes that define it.
Honda's single-cam V-6 is revised from last year with small increases in output but substantial improvements in fuel economy. Variable Cylinder Management, now standard across the board, is capable of turning the six-cylinder into either a four- or three-cylinder engine during low-load cruising, and with the Touring models' six-speed automatic (a five-speed is standard on other trim levels), the Odyssey returns the best EPA fuel economy at 19/28 mpg city/highway. That's the same as the Nissan in city fuel economy and a 3-mpg advantage on the highway versus the closest competitor.
Toyota offers a four-cylinder engine rated at 19/24 mpg, but that's only a 1-mpg advantage over the V-6 Sienna, and a previous drive with the 187-hp engine confirmed that it's a powertrain best avoided. The 266-hp V-6, though, pulls strongly, with a penchant for low-end thrust where the other engines are happier at the top of the tachometer.