Originally Posted by SRT6 Gang Member

I don't know what an ideal afr should be, though i would suspect it should be a straight line, i.e. 12.0 +/- .2 through redline. Not starting at 11.8 and gradually leaning out on the top end @ 12.8. You are correct 11's are on the rich end and 13's are on the lean end. The lower your number the richer you are, the higher your number the leaner you are.

Yes, starting at 11.8 and and ending at 12.8 is acceptable, I presume. The gradual increase in afr is a leaning condition, you are not running lean, but your ending afr is noticeably leaner than what you started out at. I think all of use have this (acceptable) leaning condition and I don't think its by choice. Its a product of our fuel system and elevated boost levels.