Why would the engine fail with such low mileage?
We have a 2006 Tribeca with 100,500 miles and it runs as good as new. It's smooth, with good mileage, no misfires or vibration, and decent power even though we live at 6,500 feet.
Three weeks ago we took it on a 3,500 mile trip from Colorado to North Caroline and back, and got about 22.5 mpg for the trip. It was a little thirstier on the way out there with the car packed to the roof with our daughters stuff for college and a bike on the back, but a little better coming back even though it was uphill. That's only a little worse than the 24 mpg to Phoenix and back in 2010 when it had 60K miles.
We're hoping to get another 2-3 years out of the car. At some point soon we'll need to replace the struts, but it's not quite ready yet. Overall it's been very trouble free and a pleasure to own.