Just calculate in man-miles per gallon. 25 mpg in a minivan x7 people is 175 mpg a head.
Back when I was looking, it was between the Mazda 5 and a Dodge. The Mazda was rated a bit higher, but cost a bunch more and was a lot smaller. Purchase price and utility made the Grand Caravan a much better move despite getting worse mileage.
One of these might do the trick, if you can find one:
