With such great handling, one expects outstanding acceleration as well, but in this regard we've found past Navigators lacking when compared to the 345-horsepower Cadillac Escalade. But Navigator has a new engine for 2005, with single overhead camshafts and an unusual three valves per cylinder instead of the twin cams and four valves used previously.
Displacement is unchanged at 5.4 liters, and horsepower is still pegged at 300. Peak torque is up only slightly, from 355 to 365 pound-feet, with peaking speed slipping from a nice, low 2750 rpm up to a more fussy 3750. So on paper, Navigator still looks a little weak compared to Escalade's 380 pound-feet of torque (albeit at an even peakier 4000 rpm). We found the responsiveness from the 2005 Navigator smooth and responsive, though it lacks the sharpness of the Escalade or Infiniti QX56. Lincoln designed its new V8 to produce strong torque across the entire operating range, and it does, making the Navigator a good vehicle for towing. The new engine is a few pounds lighter as well, with a new and stiffer iron block that reduces noise and vibration. Lincoln says the three-valve design helps reduce emissions. Navigator requires premium gasoline, and a 2WD Navigator is rated 13/18 mpg.
Behind this new engine is a new six-speed automatic transmission from ZF of Germany, the first of its kind in a full-size SUV. It's the same transmission that Jaguar installs in its flagship XJ sedan. Having more gears makes it possible to keep the engine operating near optimal rpm more of the time, while a wider span of ratios allows quicker launches and more relaxed cruising. We found the new automatic worked very well. It performed exactly how we wanted it to, neither downshifting nor upshifting inappropriately. It would hold a gear when going downhill, for example, and on one descent it provided enough engine braking to eliminate the need to use the brakes.
Now standard on all Navigators, AdvanceTrac stability control monitors factors such as yaw rate and steering wheel position to determine whether the Navigator is turning as its driver intended. The system can reduce engine power or selectively apply the brakes at individual wheels (something no driver can do) to correct a skid almost before it starts. Roll Stability Control monitors body roll and takes corrective action to reduce the chance of rolling over. Neither system can violate the laws of physics, but in many cases they can prevent a moment's inattention from turning to disaster. Next Page