Cost
The destination charge is a standard charge for transporting the vehicle from its point of origin to the dealer. It costs almost the same to get the Mercury to the dealership as the Dodge Nitro.
With respect to gas mileage, the Mercury Mariner bests the Dodge Nitro.
Producing an accurate fuel economy evaluation is so difficult that some think not even the federal government can do it, but it looks as though the Mercury Mariner is the winner with respect to fuel economy.
The Mariner isn't much costlier than the Dodge Nitro in terms of MSRP.
The Mercury Mariner will save you a bundle at the pump every year compared to the Dodge Nitro.
The Dodge Nitro will cost you a bundle in gasoline every year compared to the Mercury Mariner.
Utility
Neither the Mercury Mariner nor the Dodge Nitro has a marked advantage in terms of seating capacity.
Towing is significantly more the Nitro's forte than it is the Mercury's.
Convenience
You will most certainly have to visit your friendly gas station more often with the Nitro than with the Mercury.
Comfort
While the front cabin in the Dodge Nitro offers a bit more head room than the Mercury Mariner, there really isn't much of a difference.
The Dodge provides more head- and leg-room to your passengers than the Mercury Mariner does.
Dimensions
Your wallet will hurt more every time you fill up the Dodge Nitro than the Mercury because of its larger tank.
The Mercury Mariner and the Dodge compete for the same parking spaces.
Handling
With their comparable turning circles, the Dodge Nitro and the Mariner most definitely handle about the same into and out of tight spots.
Drivetrain
The Nitro's engine is considerably more massive than the Mercury Mariner's. Note that more sizeable engines may use more gasoline than smaller ones.
Torque is the force that lets you accelerate quickly, and in this respect, the Nitro is substantially more powerful than the Mercury Mariner.
Torque equals pickup, and the Dodge Nitro will have picked up and gone by the time the Mercury finally gets moving.
Warranty
The Nitro and the Mercury have the same basic warranty.