The 4Runner has a nice, smooth ride on unpaved roads, too. That's important when venturing afield because you often end up driving over washboard surfaces and rough roads. The 4Runner's well-tuned damping and progressive-rate spring bumpers are to thank here. Where the 4Runner really comes into its own, however, is when the terrain gets truly gnarly. There's lots of suspension articulation for climbing over boulders and gullies, and a host of technology for handling steep, slippery grades.

The standard V6 engine is so good that, until the 2005 models were introduced, we couldn't see a reason to get the V8 unless its strong low-rpm torque was needed for frequent towing. Toyota's 4.0-liter V6 is responsive and we never felt short-changed. It was brand-new in 2003, and it's packed with the latest technology, including fully variable valve timing, a new linkless electronic throttle control system and lightweight all-aluminum construction. The V6 is rated at 245 horsepower and 282 pound-feet of torque. Fuel economy has been improved and the V6 4x4 model gets a credible 17/21 mpg city/highway, according to the EPA (18/21 for 2WD models). The V6 is paired with the new five-speed automatic transmission.

For 2005, the optional 4.7-liter V8 features variable valve timing with intelligence (VVT-i) and an electronic throttle control system with intelligence (ETCS-i), which increases the output to 270 horsepower at 5400 rpm and 330 pound-feet of torque at 3400 rpm. The V8 models weigh about 125 pounds more than V6 4Runners, and the V8 delivers 16/20 mpg in 4x2s, and 15/19 in 4x4s.

Both engines feature a cranking system that keeps the starter engaged until complete combustion is achieved, freeing the driver from holding the key until the engine turns over. This is a feature usually associated with expensive luxury sedans.

We found the two-wheel-drive 4Runner impressively capable off road; indeed, it's more capable than some so-called SUVs equipped with all-wheel-drive. Yet ultimate traction comes from the four-wheel-drive models. It seems to us, that if you don't need four-wheel drive, then perhaps you should be looking at a different vehicle. The 4WD 4Runners are equipped with a two-speed transfer case, giving the driver a set of low-range gears for creeping over rugged terrain.

V6 4WD 4Runners are equipped with Toyota's Multi-Mode shift-on-the-fly system with a Torsen-type limited-slip center differential. The driver can shift between 2WD, 4WD High, and 4WD Low. The Torsen center differential is open in 2WD mode. It applies a rear bias in 4WD High, splitting torque 40/60 front-to-rear in normal driving conditions, providing the driver with a traditional feel and better stability when accelerating. The 4WD mode may be used in all types of driving conditions on all types of roads, from dry pavement to wet or snow-covered roads. The system gives the 4Runner a sure-footed feel because power is applied to all four wheels, improving traction. When the front wheels slip, up to 70 percent of the power goes to the rear wheels. When the rear wheels slip, up to 53 percent of the power goes to the front wheels.

The five-speed automatic transmission enhances the responsiveness and efficiency of the engine. The transmission is equipped with Artificial Intelligence Shift control, which changes gear-shifting patterns according to driving conditions and driver intent. It works well and seems to understand when you want to cruise and when you want to get with the program.

All 4WD 4Runners come with Toyota's Downhill Assist Control (DAC) system. It works similarly to Land Rover's Hill Descent Control to control the speed and progress of the vehicle down steep grades. Shift into 4WD low-range, check to make sure Downhill Assist is activated, pull to the edge of the nearest precipice, take your feet off the pedals, and steer your way slowly down the trail. Once you make the leap of faith that comes with allowing the machinery to do the work for you, Downhill Assist works very well and is easy to control. The ABS makes a noisy "dunk, dunk, dunk" sound as it lowers the 4Runner safely down the slippery slope. Gently touch the gas or brake pedals to slow or speed your progress, then take your feet off the pedals again, and the system comes back on: "dunk, dunk, dunk, dunk." Downhill Assist helps keep the 4Runner pointed in the direction you steer it, using the ABS to curb the tendency for the vehicle to get sideways on steep descents. The system will work continuously for three minutes (because the brakes will heat up with prolonged use), but Toyota officials say it only needs the shortest of breaks to continue. Three minutes is usually more than enough time to get to the bottom of the sort of uncomfortably steep descent we're contemplating here.

All 4Runners also come with Hill-start Assist Control (HAC), which is designed to prevent the vehicle from rolling backward or slipping sideways when starting off on a steep ascent. The system controls the brakes to stop an individual wheel or all wheels, preventing the vehicle from rolling backward or slipping sideways.

The Toyota 4Runner is a truck, not a car. Rather than using a unibody like the Toyota Highlander or RAV4, the 4Runner is built on a ladder frame that features full-length boxed section frame rails. Toyota steered away from using an independent rear suspension like the one on the ladder-frame Ford Explorer and many cars. Independent rear suspension offers better ride quality and allows for a roomier interior, but Toyota responds that the 4Runner's off-road capability was a high priority and that its live rear axle offers more suspension travel.

V8 Limited models offer an optional rear air suspension for improved ride and performance when towing or hauling heavy loads. The air suspension automatically adjusts the ride height according to vehicle load. The driver can raise the rear suspension when driving off road to increase the ground clearance and improve the rear departure angle. This latter feature is extremely useful in the extreme conditions where it's needed, but most owners will never go there.

A system called X-REAS (standard on Sport, optional on Limited models) improves handling dynamics on the road with no compromise in off-road articulation or suspension travel. X-REAS reduces the tendency of the vehicle to bob up and down in corners and improves handling by damping body pitch and roll. A simple system, it links the shocks diagonally through hydraulic lines (e.g., the front left shock is linked to the rear right shock). A central control absorber helps balance shock damping.

Anti-lock brakes (ABS) with Brake Assist and electronic brake-force distribution (EBD) come standard on all 4Runners. The four-channel ABS prevents the wheels from locking under severe braking, improving driver control. The 4Runner's ABS has an off-road algorithm to improve stopping performance in slippery conditions, a great feature. EBD automatically balances the braking force front to rear for shorter stopping distances. Brake Assist helps a driver who may not be pressing the brake pedal hard enough during an emergency stopping situation by generating additional brake force to assist the driver. We found the brakes worked well. They felt a bit sensitive on the 2005 4Runner V8 we drove, but we quickly adjusted to them.

The 4Runner's fuel tank was specifically designed for off-road use. The tank is plastic, offering better protection against corrosion, rust-through and connection leaks. Yet the plastic tank is armored by a steel case for protection against debris kicked up by the tires, or rocks off-highway enthusiasts might encounter.