GMC's Canyon pickup measures up as a mid-size model with body styling showing design cues from Sierra. Cabs conform as a two-door Regular Cab, the Extended Cab with two rear-hinged doors set behind the two front doors, and Crew Cab with four front-hinged doors.

Engines of in-line design motivate Canyon. The entry plant is a Vortec 2.8-liter four-cylinder unit rated for 175 hp. Optional is a Vortec 3.5-liter in-line five-cylinder that climbs to 220 hp. Either ties to a five-speed manual transmission or four-speed Hydra-Matic automatic. More across-the-board choices come with formats of rear two-wheel-drive (2WD) or four-wheel-drive (4WD) traction through an automatic active transfer case called Insta-Trac.

A new SLT package with heated seats works on Extended Cab and Crew Cab models this year, and the ZQ8 sport suspension package -- with two-inch lower ride height and 17-inch aluminum wheels -- is a new option.

The HD (heavy-duty) label for Sierra signifies work trucks stretched to king-size dimensions. And they develop top-of-class gross vehicle weight ratings (GVWR). The series provides cabs of regular and extended lengths in 2500 (three-quarter-ton) and 3500 (one-ton) models.

Muscular engines power these big rigs to the top of the heavy-duty class-- from a Vortec 6.0-liter V8 worth 300 hp or big-block 8.1-liter Vortec at 330 hp to a Duramax 6.6-liter turbo-diesel for 310 hp. A new Duramax turbo-diesel, coming later in 2006 and linked to a new Allison 1000 six-speed automatic transmission, will deliver 360 hp with torque rising to 650 lb-ft. Sierra Performance Edition for 2WD Extended Cab truck nets the high-output 6.0-liter V8 at 345 hp.

And for Sierra 3500 Crew Cab long-box with single rear wheels, new chrome-clad steel wheels go to the option list.

Sierra trucks in half-ton 1500 series include Wideside and Sportside body styles, rear 2WD and 4WD modes, and cabs of regular and extended lengths. In addition, Sierra offers the deluxe and powerful Sierra Denali rigged with an all-wheel-drive (AWD) system. For 2006 the series adds a Sierra Extended Cab with short cargo box and a new SL Crew Cab base model.

Vortec engines for Sierra range from a 4.3-liter V6 at 195 hp and the 4.8-liter V8 with 285 hp to a 5.3-liter V8 pumping 295 hp or 310 hp, plus a 6.0-liter V8 worth 300 hp or 345 hp for Denali. A hybrid electric version called Sierra Hybrid saves about 12 percent on fuel, using the 5.3-liter V8 with an electric motor plus optional 4WD traction. And a new VortecMAX Performance Package for Sierra boosts tow capability with the high-output Vortec V8 added with 345 hp.

Envoy the mid-size wagon comes in regular-length and stretched XL editions with extra room in the cabin for a third row of seats. Deluxe variations -- Envoy Denali and Envoy XL Denali -- stock luxurious comforts with choices for 2WD or 4WD traction.

Denali models tote a Vortec 5.3-liter V8 engine rated at 300 hp. The all-aluminum plant applies GM's innovative Displacement on Demand (DOD) technology that automatically pares the number of cylinders engaged in the combustion process when boosted power is not needed. Standard powertrain for Envoy and Envoy XL is a 4.2-liter in-line-six engine that runs to 291 hp.

External styling of Envoy changes on 2006 issues with chrome accents applied to front grille and bodyside moldings. Also, safety equipment improves with GM's StabiliTrak electronic vehicle stability control system going to every Envoy as standard equipment.

GMC's full-size SUVs consist of the Yukon and stretched-length Yukon XL plus deluxe companions Yukon Denali and Yukon XL Denali. Denali editions are lined with leather and carry a permanently-engaged AWD system and smooth Autoride continuously-variable suspension.

Yukon's powertrains for 2006 are a 4.8-liter V8 with 285 hp and a 5.3-liter edition bumped to 295 hp. Yukon XL 1500 stocks the 5.3-liter V8, while the 2500 XL and both Denali models use a 6.0-liter V8 spiked to 335 hp. Further, the big-block 8.1-liter Vortec V8 worth 320 hp is available for Yukon XL, and Yukon plus Yukon XL may be equipped with a Flex-Fuel 5.3-liter V8, which can operate on fuel that contains up to 85 percent ethanol derived from corn.

A tire pressure monitoring system (TPMS) drops into the 2006 Yukon 2500, with power adjustable pedals and extendable camper mirrors optional for all Yukon equipment groups.