DX, take out that space after SIGNED in the LOR equation (as Rich pointed out), it should work then. Even so, remember, it IS a RATIO, not an absolute number, so the way to see what it does is to see how fast it goes to -1 each time you add the ACES IV at fillup time, say with 87 gas, while updating the tune itself (87 then 91 then 93 & so on). no need to say that datalogging is absolutely critical to determine remaining headroom and avoid limphome mode.