A five-cylinder engine is an unusual configuration for a U.S. vehicle, but German automakers have been using them for years. Mercedes-Benz offered five-cylinder diesels in the 1970s, and Audi's premier engine was an inline-5 from 1977-91. More recently, Volvo has adopted the straight-five idea. All of these engines produce a distinctive, siren-like sound at full throttle, and so does the five-cylinder Colorado. At cruise, however, GM's five-cylinder is quiet, and there's no indication that it's anything out of the ordinary. If you like inline-6 engines better than V6s, then you'll like the inline-5 just fine. It's much more responsive than the four-cylinder and delivers quicker acceleration. It's also smoother. Just don't mention the number of jugs it has in a cowboy bar.
Both Colorado engines were derived from the Vortec 4200 inline-6 used in the Chevy TrailBlazer. GM lopped cylinders off the six to get the five and four. These are modern engines featuring all-aluminum construction, dual overhead camshafts with four valves per cylinder, variable valve timing, electronic (drive-by-wire) throttle control, and a high 10:1 compression ratio. Along with a larger displacement for 2007, both Colorado engines also benefitted from larger intake and exhaust valves, revised cam profiles, new 2M electronic control module, and a number of refinements to reduce noise.
Colorado accelerates decently in traffic, and its Hydra-Matic 4L60 four-speed automatic transmission shifts smoothly. But goose it on loose gravel or dirt, and the traction control system shuts down the power and the Colorado bogs. We discovered this while trying to merge into fast-moving traffic from a pebbly roadside. The traction control override button, located high on the dash, can be used in such a situation, but obviously you'll need to think that through in advance. In snow, however, the traction control should help in taming the pickup's lightly loaded rear end.
The brakes are big and meaty and certainly should be enough for any load the Colorado is rated to carry. Using front discs and rear drums, they are easy to modulate for smooth stops and work well when applied. Standard four-wheel ABS helps the driver maintain steering control in an emergency braking maneuver. It does its job neatly, keeping the truck in line even when slamming on the brakes on a gravel road.
All models offer stable and predictable handling. The suspension is firm enough to handle hard stops on pavement without drama. The Colorado is a truck, however, so it doesn't corner or stop like a car. We found it tended toward understeer, plowing in corners when pushed beyond the grip of the tires.
We were pleased with the operation of the four-wheel-drive system. There's no doubt when it engages: There's a small clunk when it shifts into 4WD HI (which can be done on the fly) and a bigger clunk when it shifts into 4WD LO (requiring the vehicle be stopped and in neutral). No full-time all-wheel drive is available; this is a truck-style part-time four-wheel-drive system and should not be used on dry pavement.
The Z71 models ride well for a pickup with an off-road suspension. We were able to test a Z71 in deep, sucking mud. We climbed a greasy, rocky hillside that, in the winter months, becomes Pennsylvania's Jack Frost ski resort. In neither case did the Colorado disappoint us. Next Page