• The GMC Envoy is the standard 5-seater truck-based midsize SUVs. It's capable of hauling heavy loads and negotiating rugged off-road terrain.
• The Envoy comes with a six-cylinder Vortec 4200 engine and a four speed automatic transmission. Customers have a choice between two-wheel and four-wheel drive and packages available include the SLE, SLT, and Denali. With as many options as the GMC Envoy has, customers can specifically customize their own vehicles. Each trim on the Envoy add increased numbers of features like leather upholstery, automatic climate control, eight-way power seats for driver and passenger with memory on the driver's side, a driver information center, audio controls on the steering wheel, separate rear-seat audio controls or heated outside mirrors with turn signals. The Denali package includes a 5.3-liter V-8 which features GM's Displacement on Demand technology, which idles half the cylinders when cruising to enhance fuel economy.
• For 2006, the Envoy comes standard with StabiliTrak electronic stability control with Proactive Roll Avoidance, GM's electronic handling system for safety.

The standard Envoy is a five-passenger SUV with two rows of comfortable seats. The SLE and SLT models are compelling alternatives to the Ford Explorer and other mid-size SUVs. Stable and responsive with excellent road manners, the Envoy comes with a smooth, powerful inline six-cylinder engine that has been updated for 2006.

The Envoy Denali is equipped with a more powerful V8 engine that improves its performance and increases its cargo-hauling and trailer-towing capability. This optional 5.3-liter V8 features GM's Displacement on Demand technology, which idles half the cylinders when cruising to enhance fuel economy. Denali is also upgraded with luxury features and special trim, including 18-inch aluminum wheels for 2006.

The extra-long Envoy XL models are considerably longer, allowing seven-passenger seating and greater hauling versatility. Because it's longer and heavier, the XL doesn't handle as well as the Envoy nor does it feel as reassuring as the wider GMC Yukon. In short, we much prefer the Envoy and Yukon over the Envoy XL, though the latter does represent a value proposition.

Safety gets a major addition for 2006, as all Envoys come equipped with GM's StabiliTrak electronic stability control with Proactive Roll Avoidance. This system uses selective wheel braking and compensating shock absorber adjustments to help maintain vehicle control on slick and uneven road surfaces, as well as during emergency lane changes or avoidance maneuvers. It's a great system.

The XL models have been stretched 16 inches, increasing the wheelbase to 129 inches. This provides space for third-row seating. One way to distinguish an Envoy XL from the standard Envoy is to look at the rear doors. The Envoy's rear fenders overlap the rear door edges; the Envoy XL, with its length stretched amidships, has enough space for the rear edge of the rear doors to drop straight down all the way to the rocker panels. Some buyers see the Envoy XL as a less-expensive alternative to the full-size GMC Yukon. Indeed, the Envoy XL is nine inches longer than a Yukon, but it's four inches narrower.

Envoy models share their chassis and engines with the Chevrolet TrailBlazer and Buick Rainier (as well as the Saab 9-7X and Isuzu Ascender). Each of these nameplates boasts unique styling, but there are feature differences as well. The GMC offers more features than the Chevy, and the high-end Denali versions are GMC exclusives.

Envoy may be the best-looking of the bunch. It looks like it's ready to tackle the tough jobs (and it is), but the styling is conservative and upscale. It looks more sophisticated than the TrailBlazer. Envoy's giant black grille with its big ruby-red logo says GMC in no uncertain terms.

The front end, with its distinct headlamps, round fog lights and pouty front bumper with a wide, slim slit at the bottom is clean and sleek. Strong beveled shapes extend along the sides and around the wheel wells, and help make the Envoy look imposing. It doesn't have the TrailBlazer's showy fender flares, instead housing its big 17-inch wheels inside hefty wheel openings that are part of its trapezoidal design theme. The rear bumper is stepped for its full length, and includes big round backup lights. From behind the wheel the Envoy seems to be lean forward as you look down over the strong hood, as if poised for action.

Denali models are distinguished by their chromed honeycomb grille, body-color bumpers that reach lower to the ground, body-color mirrors, and 18-inch polished aluminum wheels. Running boards, which also serve as stone guards, are integrated into the rocker panels.

While the standard Envoy is a handsome vehicle, the proportion of the XL models make them look ungainly. They look too long in the back relative to their front proportions.

The 4.2-liter six-cylinder engine that comes standard on the Envoy is smooth and powerful, and it's a perfect companion for these vehicles. This engine is a modern inline-6 with dual overhead camshafts, four valves per cylinder, and variable phasing for the exhaust cam to produce 291 horsepower and 277 pound-feet of torque. That's significantly more than the 210 horsepower produced by the 2006 Ford Explorer's 4.0-liter V6.

GMC's 4.2-liter six is EPA-rated 16/21 mpg city/highway in an Envoy 2WD.

It's an excellent engine, and with its broad and bountiful torque, the transmission doesn't have to downshift excessively to generate power. Stand on the gas and the full-throttle upshift comes at about 6000 rpm, and the engine feels like it's only striding, not screaming. About 90 percent of the GMC's peak torque is available at just 1600 rpm, and it's still there at 5600 rpm. That means quick response at any engine speed, allowing the Envoy to bound past trucks on steep uphill two-lanes.

The smooth-shifting four-speed automatic transmission is the proven Hydramatic 4L60-E, used in GM applications from Corvettes to Cadillac Escalades, and used for both the 4.2-liter inline-6 and 5.3-liter V8. A 3.42:1 rear-end ratio is standard for maximum economy, but ratios of 3.73 and 4.10 are offered for easier towing. With so much torque available, we couldn't discern a significant improvement in acceleration performance with the 4.10. Towing was a high engineering priority, and an Envoy is rated to tow 6300 pounds with 2WD, 6200 pounds with 4WD.

The 5.3-liter V8 is standard on the Denali models. It develops 300 horsepower and 330 pound-feet of torque, which is a bit more power than the 2006 Explorer's optional 4.6-liter V8. An Envoy Denali is rated to tow 6600 pounds with 2WD, 6500 pounds with 4WD. All Envoys come with a trailer hitch platform and seven-wire trailer harness.

The V8 features GM's Displacement on Demand technology, which shuts down four of the eight cylinders when they are not needed, for up to 8 percent better fuel mileage under light-load conditions. The engine-management computer instantly revives the sleeping cylinders the second the driver demands more go. This all happens transparently and is undetectable in normal, everyday driving. The 5.3-liter V8 is EPA-rated 15/20 City/Highway mpg.

Once underway, the Envoy feels smooth and stable, even at high speeds. It rides smooth and car-like at lower speeds without being overly soft in corners. Yet it's sufficiently compliant for stable handling on bumpy roads. We found the rear end stayed impressively planted when going over washboard surfaces at high speeds. The Envoy is designed to lean exactly 5 degrees in corners, then stop leaning. Envoy's track is among the widest in the class (wider than the 2006 Explorer and the Toyota 4Runner, for example). Also, the engine is mounted relatively low, lowering the Envoy's center of gravity. A low center of gravity means better handling and stability.

The available load-leveling air suspension is intended to provide a more luxurious ride. It uses a silent air compressor, which yields one additional benefit: a 22-foot air hose that attaches to a small valve in a compartment in the cargo area, and can be used for filling everything from tires to toys. Off-road, we found that the load-leveling suspension bottomed easily, signaling a need for the optional skid plates. Our test model had the skid plates, of course, which we dragged in soft sand, chugging easily along at 5 mph in Auto4WD. On low-speed whoop-de-doos, the front end bobbed up and down more than we would have liked.

The Envoy's four-wheel-drive system, called Autotrac, works well and features four settings: 2WD, Auto4WD, 4HI and 4LO. Auto4WD automatically apportions p.

The GMC's seats seemed more comfortable than those in the Chevy. The Envoy's seat cushions are longer, wider and thicker, and offer noticeably more side bolstering, though the seat bottoms could use more support.

The leather upholstery in the Envoy SLT is plush, but the cloth in the SLE grips the driver better. Head, hip and legroom are comparable to that of the Ford Explorer. As with Explorer, the sides of the seat bottoms are not fully trimmed around to the inside. On the SLT, the driver's bucket is eight-way power adjustable, with two-way lumbar support and optional heat. The shoulder belts are fixed to the seatbacks; we'd prefer adjustable-height anchors.

The brushed nickel interior trim looks classy. The SLT gets burl woodgrain trim on the center stack and console. Wood is also used around the light switches and the switches on the door armrests. Four big round registers for heating and air conditioning look stylish and purposeful in nickel. The four-spoke leather-wrapped steering wheel comes standard, and on the SLT it includes climate, audio, and cruise controls. Overall, the dash looks a bit choppy, not smooth and organic. Instrumentation is complete and clean, however. A big tachometer is on the left, speedometer in the center, and on the right are smaller gauges for water, battery, gas and oil.

SLE's manual climate controls use sliders, which seem like a throwback in technology, while the SLT's excellent digital controls use round knobs. Turning a knob is easier than sliding a lever, especially when bouncing around on rough roads. Both systems feature dual zones so temperature can be controlled separately by driver and front passenger. In XL models, rear-seat passengers get their own temperature control, which can be controlled by the driver, an important feature for dogs as well as people on hot summer days.

The center console features an enclosed compartment, an open storage bin, with a pair of superb cup holders forward of the shifter. The emergency brake lever is located there. Pockets in the front doors and behind the front seats are provided, but we'd like more places to put stuff in the center console area. Three power outlets are provided in the center stack, though unfortunately none have power when the ignition is switched off. Behind the rear seat is a small hidden compartment under the floor, a cargo net (on SLT), and another power outlet. Rear-seat headrests conveniently flip down to give the driver a better view to the rear.

SLT's overhead console includes a sunglasses holder, Homelink universal transmitter and an optional Travelnote digital recorder ($85), which allows the driver to verbally record phone numbers while on a cell phone. Interior lights abound, including reading lights.

The optional Bose audio system with six-disc in-dash CD player offers outstanding sound quality and adjustment versatility. All Envoy audio systems include RDS (Radio Data Systems) technology, allowing the listener to search for stations by type, display song and artist information, and provide traffic and weather updates.

OnStar, GM's telematics system, is optional on all models and we recommend it both for its safety and convenience features. OnStar includes hands-free cell phone communication, automatic crash reporting (set the airbags off and they'll send out the rescue teams), automatic theft reporting, remote unlocking, and other services. Onstar's latest (Gen 6) technology improves voice recognition and hands-free operation. For 2006 a system has been added to send accident information automatically to participating 911 systems in the event of a crash to facilitate emergency response. More often, you'll use OnStar for directions to an ATM or gas station or for recom.

NewCarTestDrive.com editor Mitch McCullough is based in Los Angeles.