2005 Chevy Suburban Base Engine & Drive Test

The more sophisticated, Autoride suspension ($1,120-$1,170) uses computer-controlled shock damping to improve ride quality over uneven pavement. Whether towing a horse trailer or picking up the soccer team, Autoride continually adjusts the suspension for optimum ride and handling. This technology also helps reduce dive when braking (so that the nose of the vehicle doesn't dip down unduly), and body roll (or lean) during cornering, both of which improve stability.

Handling is excellent for a big, heavy truck. The steering is responsive and doesn't isolate the driver from the road. The Suburban grips the road surprisingly well for such a large vehicle. We never lost traction while pushing hard over wet mountain roads on a rainy day in Colorado. Two of us, both with racing experience, took turns driving into wet turns as quickly as we dared and the Suburban never lost grip. We were impressed. Part of this is due to its superbly engineered chassis. The entire front part of the frame is hydroformed from one piece of metal, a design that's much more rigid than a bunch of pieces of frame welded together.

Brakes on all Suburbans work smoothly and progressively, providing stopping power without drama. Four-wheel discs with dual-piston calipers ensure good stopping performance. A Dynamic Rear Proportioning system continuously balances the front and rear brakes for maximum braking without activating the ABS. Once it does activate, the ABS allows the driver to maintain control of the steering in an emergency braking maneuver. Hydroboost braking uses power-steering fluid pressure instead of engine vacuum to reduce braking effort. That provides added safety, with more reserve power assist for braking under specific conditions. The system will continue to provide sufficient power assist to stop the vehicle even if the engine stalls or is turned off.

StabiliTrak ($750) offers improved control on uncertain surfaces. StabiliTrak measures where the driver is steering against where the truck is actually heading and, when necessary, reduces engine torque or selectively applies the brakes to individual wheels to correct the Suburban's path. StabiliTrak is offered on all Suburban 1500 models, except for those equipped with the Z71 package. We highly recommend opting for StabiliTrak.

The Suburban 2500, often referred to as the 3/4-ton or heavy-duty model, is only needed for towing heavy trailers. The 2500 is rated to tow up to 12,000 pounds, which is one big, heavy trailer. The 2500 rides harsher than the 1500 because its rear suspension uses leaf springs instead of the 1500's coil springs. But the 2500 rides well, given its load range, and it makes for an outstanding tow vehicle, capable of comfortably crossing the U.S. with a big trailer with Gibraltar stability and plenty of power for those long grades through the Rockies. The current 2500 represents a big improvement over previous-generation (pre-2000) 2500s.

Quadrasteer electronic four-wheel steering ($1,995) is available for 2500 models, which dramatically increases maneuverability in tight spaces by turning the rear wheels in the opposite direction from the front wheels. The turning diameter of a With Quadrasteer, the turning radius is reduced from the standard 44.3 feet to 35.2 feet. In practical terms, a Suburban with Quadrasteer can negotiate a U-turn that otherwise calls for stopping and backing up. Quadrasteer makes it much easier to park in tight spaces, such as underground garages and crowded parking lots. But it really comes into its own when towing a trailer. Backing a trailer into a parking space at a 90 degree angle is much easier with Quadrasteer. Backing a trailer is more intuitive, turning a weekend warrior into a trailer-pulling pro; it reduces most of that trial-and-error technique that's always embarrassing when there's an audience. And you can back a trailer through tight spaces that you physically can't fit through without Quadrasteer. At highway speeds, Quadrasteer turns the wheels slightly in the same direction as the front wheels for smoother lane changes and enhanced stability. The downside of Quadrasteer is that vehicles equipped with it tend to have a rougher ride, probably due to the heavy-duty rear axle that comes with the system.

Consider cost when deciding to whether or not to order four-wheel drive: not only the initial cost, but slightly reduced fuel economy (about 1 mpg less). Those in the Sunbelt may not see justification for it. But even if you don't plan to go off road, four-wheel drive can keep you going through snow or over sandy, unpaved trails, or help pull a boat up a slippery boat ramp. If you don't get a 4WD model, we recommend ordering electronic Traction Assist ($520) or StabiliTrak ($750), which includes a traction-control feature.

Four-wheel-drive models offer several drive modes, and shifting among them is as easy as changing stations on the radio. Press 2WD Hi for dry pavement. If it rains or snows, or you turn onto an unpaved road, hit the Auto 4WD button. The Autotrac all-wheel-drive system automatically transfers power from a slipping wheel to the wheels with the best traction, providing improved control in inconsistent conditions. For serious off-road travel or deep snow, pressing 4WD Hi operates like a traditional part-time four-wheel-drive system. Shifting into 4WD Lo switches to a low-range gear for slow, sure-footed chugging through steep, rugged terrain.

The standard Vortec 5300 V8 delivers responsive performance. It develops 295 horsepower at 5200 rpm, with 330 pound-feet of torque at 4000 rpm. (Torque is the force that launches you from intersections and pulls trailers up steep grades.) The Vortec 6000 that's standard on the 2500 series is a 6.0-liter V8 rated 325 horsepower at 5200 rpm, with 365 pound-feet of torque at 4000 rpm. Like the 5.3-liter engine, it breathes through aluminum heads. The optional Vortec 8000 is an 8.1-liter V8, a big-block, all-cast-iron engine rated only 320 horsepower at 4200 rpm, but with 440 pound-feet of torque at 3200 rpm for incredible trailer-towing ability.

Suburban's automatic transmission features a Tow/Haul mode that reduces wear when pulling a trailer through hilly terrain. Pressing the Tow/Haul switch on the end of the shifter reduces the tendency of the transmission to hunt back and forth between third and fourth gears. When the transmission does shift, it shifts more quickly, reducing heat buildup for improved durability and reliability. Even when not towing, we sometimes use the Tow/Haul mode for reduced shifting on mountainous roads. Switching back to the normal mode results in smoother, more responsive shifting for everyday driving.