The LX moves out readily at part throttle, creating the sensation of power in reserve. The engine is an advanced 5.7-liter V8 shared with the Tundra pickup truck and Land Cruiser SUV. It's built for torque, and it produces a lot of it, 403 pound-feet, early in the rev range. More than 90 percent of the torque is available before 2200 rpm, so most of the time the engine is loafing along with very low effort, which adds to the quiet, untroubled manner the LX conveys on the move. This ability to provide power without revving the engine as high gives the LX a different character than the Cadillac Escalade or Land Rover Range Rover, both of which produce their peak torque at higher rpm.

The six-speed transmission has a very low first gear, complementing the engine's torque with enhanced mechanical leverage. The net effect is more power at low speeds. That low first gear is useful when creeping over rough terrain or when pulling a boat up a slippery boat ramp. For higher speeds, the six-speed offers two overdrive gears (fifth and sixth), with a sixth-gear ratio of just 0.588. This very tall cruising gear allows for quiet, effortless cruising and greater fuel efficiency. At 2000 rpm, our test unit indicated a speed of 72 mph. At speeds over 75 mph we were able to detect some wind noise coming from the mirrors, but thanks to careful noise isolation work, the powertrain is not the source of noise or vibration until much higher speeds are demanded.

Top speed is electronically limited to 137 mph. As you might expect with a four-wheel-drive of this considerable heft, the LX remains composed and relaxed even at speeds well beyond the recommended norm on America's superhighways. In bad weather, the LX really comes into its own, with a Torsen limited-slip center differential biasing torque to maximize traction.

Drawing from its Land Cruiser heritage, the LX has the guts of a true 4x4. The four-wheel-drive system has four modes, actuated by a toggle switch on the center console. It's possible to lock the center differential in high range or low range, or leave it open in either range. Normally, most people will be operating in the unlocked, high range mode, which should deliver the best mileage. When there are patches of ice or water on the road, locking the center differential helps maintain grip as individual wheels encounter slippery surfaces. When the going gets really bad, such as an ice storm or if deep mud blocks the path, locking the center differential and using low range would supply maximum balance to move forward without getting stuck.

The Lexus LX does not offer a locking differential in either axle, relying instead on electronic traction control (A-TRAC) to prevent wheelspin. Our considerable experience with A-TRAC is that it provides enhanced traction and off-road capability sufficient for any unplanned event, and then some. The one trick the Land Cruiser has that the Lexus does not have is its Kinetic Dynamic Suspension System (KDSS), with variable-rate anti-roll bars that allow greater articulation in extreme conditions; so the Toyota may be better suited for those who expect to use their SUV as an off-road vehicle. But it has to be really creepy-crawly rugged for this advantage to come in. Both the Lexus and the Toyota have multi-terrain ABS, which works at low speeds on-road or off, a great feature because it improves braking performance on gravel roads.

Crawl Control is designed for use on steep downhill trails when control is the highest priority. It holds back the vehicle (using ABS-related techology), making sure the speed is appropriate to the steepness of the terrain, so all the driver has to do is keep his or her feet off the pedals and steer; the system helps keep the vehicle going down the hill straight, so the rear doesn't start coming around and you don't end up sliding down the hill sideways until you're stopped by a tree or a rock. This could also be used when coming down a steep hill, such as a driveway or side street, in icy conditions. Both the Lexus and the Toyota come with Crawl Control.

The Lexus LX suspension supplies a mix of ride quality and cornering capability consistent with other large, multi-passenger luxury vehicles. Some vehicles in this class use air bag suspensions, but in the LX coil springs are used on all four corners, supplemented by an active variable damping system (AVS) that controls body pitch and dive. The combination is effective (and you can't get it on a Land Cruiser). We noticed the LX squats very little upon hard acceleration, the front stays level when we got on the brakes, and in general, the vehicle stayed composed during spirited driving.

The level of suspension damping is selectable. It's possible to select Sport, Normal, and Comfort damping via a switch on the dash, which allowed us to tune ride quality depending on the road surface. We preferred Comfort for highway driving and for driving around the neighborhood and around town. We switched to Sport when faced with a mountain road with a lot of side-to-side transitions. We found the difference between Normal and Comfort relatively small, but the difference between Sport and Comfort was definitely discernable.

Parking and maneuvering a big SUV can be challenging at times. Parking for the LX driver is made easier by its low-effort steering at slow speeds. Driver visibility is challenged, however. From the driver's seat of the LX, we found the hood to be tall visually, making it hard to keep track of the right front corner. Rear visibility, meanwhile, is compromised by headrests and sheer height. Fortunately, clever electronic systems come to the aid of the driver.

One such system uses wide-angle cameras located in the front grille and passenger-side mirror to give the driver an enhanced view along the front and side of the vehicle by projecting images of these blind spots on a split-screen display. Another system uses ultrasonic sensors to warn of contact with objects around the front, rear and corners of the vehicle when parking. We found that operating these parking aids simultaneously was tremendously beneficial in tight quarters, making parking easier, quicker and safer. They all work together intuitively, though the driver needs to exercise care and patience when using them.

Powerful brakes help slow this big SUV safely down from high speeds. They include large ventilated disc rotors with multi-piston calipers, enhanced by numerous active safety systems. These include Brake Assist (shortening stopping distances in emergencies), all-terrain ABS, and Electronic Brake Force Distribution to balance braking on slippery surfaces. The all-terrain ABS is particularly helpful in reducing stopping distances on gravel roads and we consider this an excellent feature.

We towed an 8,500-pound trailer for an hour or so with the LX 570 and found the engine and transmission had no trouble hauling the load up hills, as we expected. The downhill side is often the bigger challenge, as both brakes and transmission are part of what it takes to maintain control. We found that the transmission will downshift on its own, from sixth to fifth gear then to fourth gear, to enhance engine braking and fuel economy. The uphill/downhill shift logic seems flawless, responding to very slight tip-of-the-toe throttle inputs. But for those times when manual control seems called for, there is a sequential shift mode that gives the driver this control.

All Lexus vehicles offer a Pre-Collision System (PCS), available on the LX as an option. (It's integrated with the optional Dynamic Radar Control.) Though pricey, PCS is an innovative safety system that is enabled by the use of radar. With the Pre-Collision System, the car's radar can determine if a crash is unavoidable. If that ever becomes the case, the system tightens up the seatbelts, increases brake sensitivity and applies maximum braking force when the driver touches the brake. By reducing the speed at impact, and positioning the occupants, PCS allows all the other built-in safety systems to work better. According to Lexus engineers, scrubbing off just a little speed at the last second can be enough to save lives. While you don't want to crash at 35 mph, it's far better than crashing at 55 mph.