Since many people are claiming big improvements with their HHO systems, but there were no verifiable hard data posted here, I'm giving all HHO owners a 'can't refuse' offer:
I'm willing to pay for the gasoline, plus a reasonable amount for your time ($100 or $12/hour, whichever is higher) to have your mpg tested.

Where's the catch? I will be there and do the fill-ups, but let you do the driving. The drive must be at least 150 miles one way, 300 miles total, should take place off-peak, and using cruise control when the conditions are good. There must be an easy way to disconnect and reconnect the electrolyzer.

I strongly prefer local 'driving' (i.e. Seattle, WA to Portland, OR, and back), but other arrangements are possible.

 

the HHO only work for the people who sell them..I have 8 that I made the last one is the best one so far .It cost about $60.00 to make I when from 16 mile to 23

 

Hmmm.. that's a nice offer. Only, I don't have an HHO. Too bad.