|
Don't expect any big gains for improving fuel economy without hurting performance. The factory a pretty good job in this respect. The problem with leaning the AFR target at cruise is that you will also see a loss in engine torque which will require more throttle which will then meter more fuel and you are back to square one. You can problem get some minor gains by leaning AFR slightly and then adding a small amount of advance (2-3 deg) at cruise conditions. The factory couldn't get away with these changes due to emission constraints (primarily NOx emissions concerns). But the effects on mpg would be small and take some very controlled testing to quantify. Probably too controlled to street driving.
|