A 2.8-liter four-cylinder engine comes standard in most models, rated 175 horsepower. A 3.5-liter five-cylinder rated 220 horsepower is optional ($1,000) on most Colorados and standard on some upper-level models. A five-speed manual transmission is standard with either engine, with a four-speed automatic ($1,095) optional.

Regular Cab, Extended Cab, and Crew Cab models are available. Trim levels have been expanded for 2006.

The only base-level models are commercial-grade trucks. These are available as a Regular Cab 2WD ($15,330) or Extended Cab 2WD ($17,705), plus new Regular Cab 4WD ($19,125) and Extended Cab 4WD ($21,475) models. All come with hose-it-out vinyl floor mats and durable vinyl seating, ideal for muddy-boot applications (and situations where the buyer isn't the same person as the driver). Air conditioning is standard, along with tilt steering and cruise control. Four-cylinder engines come standard, but five-cylinder engines are available. All come with the standard Z85 suspension. An LS badge, which was the deluxe Colorado last year, now simply means the commercial truck with a 60/40 split cloth bench seat. Prices are exactly the same, although the option list expands somewhat. Options includes carpeting ($70).

To move up to what was an LS truck last year, you now must order one of three sub-levels of LT trim. 1LT adds a recline feature, center armrest, and upgraded fabric for the 60/40 split bench seat; plus leather wrap for the steering wheel and AM/FM/CD/MP3 audio. 2LT adds power windows, mirrors and locks with remote keyless entry, and makes the automatic transmission standard. Choosing 3LT makes the five-cylinder engine standard as well, plus front bucket seats and an auto-dimming rear-view mirror with eight-point compass and temperature readout. And again, the option list expands at each level.

The Z71 off-road suspension requires a minimum of 1LT trim, and adds an automatic-locking rear differential, P265/75R15 on/off-road tires, and a Smoke Gray grille and wheel flares. Ground clearance at the rear differential is 8.4 inches. Order 4WD and you get skid plates, too.

The ZQ8 sport suspension requires 2WD and 3LT trim. The ZQ8 rides lower than base models, with a slight forward rake, and comes with P235/50R17 tires on 17-inch aluminum wheels. A monochromatic paint scheme and fog lamps add visual distinction.

Taking the ZQ8 concept one step further is the Colorado Xtreme, which drops the already lowered ZQ8 suspension down another 1.6 inches and mounts gas-charged shocks and bigger-diameter P235/50R18 wheels and tires. A unique grille, tailgate spoiler, and side-sill extensions add exclusivity to Xtreme's appearance, along with monochromatic paint schemes limited to red, black, blue, or yellow.

As before, content at any trim level can vary with suspension package and cab style, and not every cab style is offered with every suspension and trim combination. It's all very complicated, so we suggest you see your Chevrolet dealer for details.

Power windows, locks and mirrors are optional ($500) on 1LT. XM Satellite Radio ($325) is available with any LT trim, while Gen 6 OnStar ($695) requires 2LT at minimum. Crew Cabs with 3LT offer optional heated, power-adjustable bucket seats with leather seating surfaces ($340) and a power sunroof ($695). A new Sun and Sound package ($795) for 2006 will bundle the sunroof with a six-disc in-dash CD changer.

Safety features include curtain-style side-impact airbags designed for head protection that come standard on Crew Cabs, but are optional ($395) on other models. Four-wheel anti-lock brakes (ABS) come standard on all models.