C4

This medium-duty cab-and-chassis nameplate was introduced for the 2003 model year as part of GM’s commercial truck lineup, where it sat in the 4,500-pound-class series alongside related heavier variants. It was aimed at vocational buyers who needed a durable conventional cab for upfitter bodies, service work, towing, and other fleet applications rather than a consumer-focused pickup role. The truck carried the TopKick-era medium-duty styling and hardware that helped define GM’s commercial range in the 2000s, with the designation appearing in GM parts and VIN references through the 2009 model year. After 2009, the nameplate was discontinued and did not continue into the next commercial-truck generation, making this a single continuous production run.