A/F @ Cruise SD

[dirt_track_racer_81]

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

[Chevy366]

Have read before that in "Lean Cruise Mode" it got as lean as 16.1 but that was at lite loads and some timing added .
I have tried 15.4 and 15.7 , but PCM keeps pulling me back to 14.9-15.0 ([B3647] set at 15.17 in main cells and 15.4-15.7 in cruise cells) , COS3 .
I think RonC has had good success with COS3 and leaning cells .

[dirt_track_racer_81]

Have read before that in "Lean Cruise Mode" it got as lean as 16.1 but that was at lite loads and some timing added .
I have tried 15.4 and 15.7 , but PCM keeps pulling me back to 14.9-15.0 ([B3647] set at 15.17 in main cells and 15.4-15.7 in cruise cells) , COS3 .
I think RonC has had good success with COS3 and leaning cells .

ive never had any problems with going back t0 14.6..always runs what i command..just wondering if any one runs any leaner

[Chevy366]

I C , sorry , 15.4 , 15.7 is all I have ever tried .