We tested the Z71, a Colorado model with faux four-by-four trim that gives it the look of a serious off-roader without it being a four-wheel-drive vehicle. The truck had a 3,200-pound tow rating, but the twin-cam in-line-5 engine-which delivers 220 hp through a five-speed manual transmission to the rear wheels-felt overwhelmed hauling two waterbikes on a trailer. Plus, there was an unpleasant cabin thrum whenever this engine was required to give output. With the 1,570-pound rig, the Colorado Z71 took a reasonable 12.1 seconds to reach 60 mph, but it needed 14.4 seconds to complete a third-gear passing maneuver. Stopping performance was more satisfactory: The combination of fat tires, more than adequate brakes, and standard ABS halted the rig from 60 mph in less than 200'. At the launch ramp, the optional electronic traction control system ($295) kicked in when we were pulling the waterbikes out of the water, causing the engine to stop dead. Disabling the traction control system and relying on wheel spin to get the rig up a slippery surface can avoid this problem. Fortunately, a limited-slip rear axle is included with the traction control option, so both rear tires are digging in when you engage the clutch.