The truck..2000 Chevy Ext Truck, 6.0 230/226 cam, 2001 Calibration with COS 3, tuned speed denisty with no maf, I was just wondering what other people are setting their Air Fuel Ratio's at cruise to?? I have mine set to 15.5..any one going any leaner...I've read on some articles that 15.5 is the most efficient for gas mileage