By Heather Burlingame, Senior Production Editor | September 28, 2010

The in-line 6-cylinder (I-6) family of engines for the company's 4000 and 7000 Series and 8500 trucks features cooled EGR and variable-response turbochargers. The fuel system offers more precise timing control for optimized fuel delivery, and G2 injectors are smaller than previous ones to allow room for 4 valves per cylinder. Horsepower ranges from 210 to 340.