Nope, not nearly the same. That's not full 12amp (which parent post claims for Outlander PHEV). Per Sienna manual, the 120V outlet is limited to 100W (less than 1amp). http://www.tsienna.net/power_outlets-322.html

For this level of power, you can get a 12V DC to 120V AC adapter that works on pretty much any car.