Two Minivans with some similarities, but otherwise different in most aspects such as the horsepower, ground shadow size, maximum occupancy, starting price, fuel economy, and height. First of all, there is a notable difference in the starting price of the 2015 Ram Promaster City, which is $6,270 less than the base MSRP of the 2016 Honda Odyssey. Also, the 2016 Odyssey has a more powerful engine and gets 2 mpg less than the 2015 Promaster City. In addition, comparing the dimensions we see that the Odyssey is significantly larger, although it's slightly shorter than the Promaster City. And finally, there is a difference in the number of passengers; the Honda Odyssey seats three more the Ram Promaster City. Among similarities is the body structure.