I must have missed that statment...
If you want to come at this from the perspective that Warren was referring to his normal gas mileage, before the drop, be my guest. IMO he is addressing a drop after short term improvement. It seems to me he could have simply said, “I immediately got vastly improved mileage after installing the device.” and have left it at that. Instead he addressed a drop off in improvement. That doesn’t exactly destroy his credibility with me. Unless I missed it, the article fails to clarify if this drop made the resulting mileage less than the average mileage before the device was added in.
BTW, after rereading the article, I’m not convinced the alternator couldn’t impact the overall efficiency of this device.
Is there improved mileage or not? Have there been controlled tests to find out?