This weekend I sealed up all the leaks in my electrolyzer again and siliconed the edges of the plates. I am also already tuned to 15.6:1 AFR. The result is 36.28MPG while doing 75mph on the hwy with 85mph bursts. This is a 8-9mpg increase from what I would usually get. I am guessing that I got more out of the HHO because of the leaner mixture. In either case I am happy with the results because I am only pulling maybe 10amps max and gaining so much. When I was testing the electrolyzer using a car battery charger, it was pulling 4.2amps while being pretty warm. So I am guesstimating that its not pulling more than 10 when it is under its operating temperature under the hood.