Not at all It only gets slightly warm even after an hour drive. The amps raise about 5 amps after an hour. I'm just starting out so I'm staying at a 5amp draw for the first tank of gas and them I plan on increasing by 5 amp incremants each tank until I get the best mpg's. I use a 30 amp PWM to control amps.
I'd say bump up the eletrolyte ratio and make note of how much you used so you can duplicate it.If it were me (and I'm not telling you to do it)with amps that low I'd double what I was using and try again.If it's too much you know the correct ratio lies between your previous mix and the new one.
I checked my mpg's today i went from 15 to 13.5 . I'm gonna try 10 amps next. I get about .25 lpm @ 5amps and .5 lpm @ 10. I'm working my way up slowly to see my best results. PS I get about 15 amps before knocking down with pwm.
`99 F150 4.6L 5 speed
This is only my opinion but it sounds like your not producing enough hho to see any mpg gains.To see any real results you need to produce at least 3 lpm.But here again this is only my opinion.I'm running a 5.7 liter hemi in my truck and 4 lpm isn't quite the ammount that I need.But so far with that much I've increased mileage from 14.5 to 16.5 with 4 lpm(and other mods).