The Mercury Mariner I is worst that the Nissan Terrano II in the category of fuel tank size. The Nissan Terrano II is able to take by 15 % more fuel than its rival.
The wheelbase of a car equals the distance separating its front and rear wheels. The wheelbase notably affects the driving because of more desirable vehicle's weight distribution. Nissan has 23 mm longer wheelbase distance than Mercury. Wheelbase dimensions are important to the stability and steering. Hence, the mass of Nissan Terrano II should be better distributed and driving should be easier and safer.
The Nissan Terrano II 2.4 i 12V 118HP manual is 6 percent longer in relation to the Mercury Mariner I 2.3 155HP. Long cars have roomy cabin and usually provide more storage space. Although the Nissan Terrano II 2.4 i 12V 118HP manual seems to be better choice for families or persons who appreciate convenient rides, the Mercury Mariner I 2.3 155HP may be more appropriate to women because it will not make troubles with parking and will be more maneuverable.
The higher a car is, the the more convenient is a boarding it and greater possibility of putting big amount of thinks to it. The difference between these two cars of 7 percent in favor of the Nissan Terrano II is insignificant and should not be really noticeable.