Mass is lost at the level needed to produce the energy released when hydrogen is burned. You can back into the mass lost by plugging in the energy released into the formula E=MC2
This is all about the current wave of 'flim-flam' that has arisen due to the high price of fuels.
I agree these units are a scam. If you buy one, buy it here.
The mass exchange is too small to measure on a desktop analytical balance, thus cannot possibly be recognizable for purposes of this discussion.
Yea, brown's gas electrolysers are nothing new; they've been in production numerous times since 1932, but they just don't produce enough boost in economy to justify the purchase price, and time it takes to install them, unless you are going to boost your compression ratio, and use water/alcohol injection, and even then it takes years to break even. Most don't keep their cars that long.