Someone feel free to chime in and correct me if I'm wrong but running meth/water you'd still be looking at the same lambda as if you where only tuning for gas. You arn't removing gas from the tune. You are adding the meth on top of it. I think generally you want to see approx .5 afr lower when spraying meth. So if you're running 11.7:1 on only gas. You should see about 11.2:1 with meth injection. I don't work in Lambda but I imagine if your goal in lambda for a/r is say .8. You'd probably run something like a .76 with meth injection.You mentioned lambda being the more accurate way of tuning. I actually have meth injection and been using AFR to 11.0 when injecting meth water. Stoic AFR of meth is like 6. How would you tune it in lambda?