Trucks bearing the bow-tie badge of Chevrolet appear in conventional formats of mid-size, full-size and super-size dimensions with Colorado, Silverado LD (light-duty) and Silverado HD (heavy-duty). Yet Chevy also promotes unconventional concepts, like Avalanche -- built with the abbreviated bed of a pickup but the six-seat cabin of a SUV.

Chevrolet's mid-size pickup comes in many versions. Cabs include a two-door Regular Cab, the Extended Cab with two rear-hinged doors behind front doors, and a four-door Crew Cab. Truck box for Colorado Regular Cab and the extended version stretches 73 inches, while the box on Crew Cab chops off 12 inches to keep the wheelbase at a reasonable length. Two new engines with in-line arrangement work on Colorado for 2007. The new base 2.9-liter four-cylinder plant with variable valve timing (VVT) delivers 185 hp, while an optional 3.7-liter five-cylinder VVT plant climbs to 242 hp.

Chevy's best-seller truck series extends '06 versions as a new generational design for Silverado emerges during 2007. Now labeled Silverado Classic, the out-going gen of Silverado trucks appears in 1500 (half-ton), 2500 (three-quarter-ton) and 3500 (one-ton) weight classes with various cab sizes and short or long box lengths. Models include a gas-electric hybrid version combining a Vortec 5.3-liter V8 with a 120-volt electric motor to improve fuel economy numbers. By contrast, sporty SS in 1500 Series Extended Cab with the short bed packs a high-output version of Chevy's 6.0-liter V8 hiked to 345 hp.

Chevy's full-size Silverado truck series earns a generational make-over which results in best-in-class power, tow ratings and fuel economy. Silverado LD (light-duty) comes in 1500 (half-ton) and 2500 (three-quarter-ton) weight classes with three cab configurations and three bed lengths, multiple suspension setups and a slew of powertrains. Base engine is a 4.3-liter V6 pumping 195 hp or 4.8-liter iron-block V8 with 295 hp. A FlexFuel 5.3-liter V8 worth 315 comes in iron or aluminum with GM's Active Fuel Management (AFM) technology on tap to save on fuel. Silverado's tow capacity climbs as high as 10500 pounds.

Equipped with a five-seat passenger compartment like the full-size Tahoe SUV, Avalanche discards Tahoe's cargo bay in favor of the shortened bed of a pickup. There's a big V8 aboard, a four-wheeling traction mechanism, and a heavy-duty automatic transmission. And the back wall of the cabin -- called a Midgate -- folds flat after the back seat tumbles forward and forms a generous extension of the truck box. Avalanche shares Tahoe's 5.3-liter V8 with Active Fuel Management (AFM), but also offers a flex-fuel (E85-compatible) version at 310 hp or a big 6.0-liter AFM V8 rated at 355 hp.