From 2003 to 2009, the Cat C7 was Caterpillar’s engine offering for medium duty class trucks. Medium duty trucks from GMC, Ford, Paccar and Freightliner could be purchased with the C7 as an engine option. Medium duty trucks cover a gross vehicle weight range of 18,000 to 33,000 lbs, have a single drive axle and are typically box trucks, flatbed trucks and tow trucks.


The Cat C7 replaced the model 3126E in the Catepillar on-road engine lineup to comply with the stricter diesel emission requirements which went into effect on January 1, 2004. Some truck manufacturers switched to the C7 as early as the 2003 model year. The engine was upgraded to meet the stricter emission requirements of January 1, 2007.