There's no sin in offering just a single powertrain, but in the 2012 Lincoln Navigator, the outmoded V-8 feels like a step down from other luxury SUVs.
Where Range Rovers and GL-Class SUVs offer a choice of V-8s, even with performance companions, the Navigator soldiers on with the same 5.4-liter V-8 it's sported for most of the past decade. It's been massaged over the years to put out 310 horsepower, but that's woefully behind almost every competitor, some of which are pushing 400 hp. Last year Ford updated the related F-150's drivetrains--but so far those new engines haven't been applied across the board to the big SUVs.
The Navigator also comes with a standard six-speed automatic transmission, with a choice of rear- or four-wheel drive. It's a combination that rates well for towing, at 9,100 pounds max, but with the Navigator's power and its curb weight of about 6,200 pounds, it's a more strained relationship. In just people-carrying duties, the Navigator can feel strained, compared to powerful new entries like the Infiniti QX56. Shifting is slick and easy, though, and the transmission turns low revs at highway speeds to reduce engine noise.
The Navigator handles solidly and stably, but you'll never forget you're in such a big, heavy vehicle. Body roll is what you'd expect from a big, heavy SUV—and expect heavy nosedive and lots of body motion during quick stops, or any change in direction for that matter—but the four-wheel independent suspension helps provide a smooth ride.