The minivan itself was a Dodge Caravan...we have friends who own a Honda Odyssey and other friends who own a Nissan Quest. I'm a little crazy when it comes to researching things so it was kind of nice to get the various perspectives. Overall, our friends seem to get about 22 mpg (on average) and that was almost exactly what we were able to get with the Caravan (I think it ended up closer to 23 by the end of the weekend but still in the same range).
To be honest, I wasn't impressed. The captains chairs in the middle row were nice-no bench to climb over, but I have the quad captains chairs in my Suburban too so that one's kind of a wash. The doors opening with the click of a button pretty much define awesome but that's sort of where the awesome ended for me. I usually average 18 mpg with my Suburan-which, I have learned, is a little high for a Suburban but my husband is always on top of it...fuel additives and oil changes and blah, blah, blah...I usually tune out after he says something mechanical and just wait to hear when he's taking it and I have to use his car. Also, my Suburban has TONS more storage room. I can tow more than just an itty bitty trailer with it. And, I can drive it in more difficult situations than a minivan could attempt (ie-out at the farm when we want to go fishing or shooting).
Although it would end up saving us some money in fuel costs, it's just not worth it to give up the space, towing and off-road capability (and general awesomeness) of my Suburban. By the end of the weekend...actually by Saturday night, Joshua had announced he was vetoing any further discussion of buying the "bloated car."
Disclaimer: Please don't take this post as an attack on minivans or anyone who drives them...they're just not for us but we know, love and respect many friends who love their minivans.