I'm sorry to say Nick's right (in a way) about the mileage---but he didn't need to be so rude...only the seller can give you the mileage of his car. But, Nick didn't even TRY to answer the more important questions you had. Just tell him "have a nice day,,,,or, if you prefer...have a BAD day!"...
Moving right along>>>
Consumer Reports will tell you all of that...and more. I "Googled-it"...and here's the link to that...you can pick & choose from all the links there.
http://www.google.com/search?hl=en&q=consumer+reports+cars&aq=2&oq=Consumer+Reports
What I like about a Jeep, is that when it's dirty, just go through some mud-puddles and put a sign in your back window, that says:
"IT'S A 'JEEP-THING'.."
Yeah baby!
If you want the mpg...& the non-roll-over factor. I'd look at the Land Rover too. (the one that isn't amphibious---I think that's the RangeRover..) Consumer Reports is a magazine that's been around for years. You can read the most recent issue in the library, or hang out for awhile at the magazine section of the nearest Barnes & Noble bookstore. Your Dad could take you there, go to a couple of new car dealerships and "kick some tires" (your Dad'll know what that means).
Good Luck sweetie, and my wish for you is that you'll not run into any more "Nicks".
You're pretty lucky to have a Dad who cares so much!