TheCarConnection.com studied reviews of the 2009 Mercury Mountaineer’s performance, drove the new SUV, and found its performance to be predictably smooth, if not exciting. While it still drives like the truck it is based on, it's stable and responsive for something that weighs 5,000 pounds.
The Mountaineer shares its engines with the Explorer. Car and Driver says "the V-8 is tons of fun in the Mustang GT, where it feels like there's an offensive lineman on meth under the hood, but in the [Mercury] Mountaineer, it's pretty snooze-worthy," although this reviewer notes "you'll definitely be able to put it to work, with a 6960-pound tow rating in all-wheel-drive V-8." In regard to the smaller engine, Edmunds comments that the Mercury Mountaineer "210-horsepower V6 looks more underpowered with every passing year."
There are some complaints about the Mercury Mountaineer transmission; Edmunds reports that it's "a bit slow to downshift." Car and Driver elaborates: "downshifts all happen at their own pace; there's no sense in asking any of them to hurry, because the Mountaineer will just ignore you." ConsumerGuide adds "the transmission shift lever blocks easy access to some climate controls." The Mountaineer comes with rear-wheel drive standard, but there is an optional all-wheel-drive system available.
With fuel economy ratings of only 13 mpg city with the V-6 (the more efficient of the two engines) and AWD, gas mileage is thoroughly unimpressive and near the bottom of its class. Many of the newer car-based crossovers will do much better. ConsumerGuide states "an AWD V8 Mountaineer averaged 15.1 mpg."
Kelley Blue Book says the 2009 Mercury Mountaineer's "independent rear suspension provides it with great stability while cornering and the variable-rate power steering returns excellent feedback to the driver." According to Edmunds, "brakes, though adequate when it comes to stopping, have a spongy pedal feel."