 Six tires are required per truck at a cost in 2009 of approximately US$42,500 per tire.Major components of the 797 are manufactured and assembled at seven Caterpillar or supplier facilities located throughout North America, then shipped to the customer site for final assembly by Caterpillar technicians.The engine is manufactured by Caterpillar in Lafayette, Indiana, and is then shipped to Caterpillar's assembly plant in Decatur, Illinois.