I installed a WAI about a 1/4 of the way into the last tank of gas. My mileage was great especially given that at least every other day I had a "bad" trip...meaning that I wasn't hypermiling perfectly...extended idling, excessive a/c use, mostly in-town trips. Hopefully I'll do better on the next tank and see that the WAI really does for me! I finally got my 90-day average at 40% above EPA...next hurdle, 50%. Hopefully new LRR tires and grill block will get me there. Not doing any EOC yet either, so there is definitely FE to be gained!
Bottom-line, it seems that Acura/Honda ECU's might positively react to warmer intake air in terms of getting better FE.