The International Harvester XT Series was a family of large pickup trucks introduced for the 2005 model year. The XT Series, short for 'Extreme Truck Series,' was sold in three main variants: the CXT (Commercial Extreme Truck), RXT (Recreational Extreme Truck), and MXT (Most Extreme Truck). These massive trucks weigh over 10,000 pounds, and are powered by a selection of diesel inline six or V8 engines. Production of the International Harvester XT Series only lasted until 2008 as customer demand was not as expected.