Some fellow is claiming he has a small device that will boost
combustion efficiency and save drivers lots of money, while reducing
emissions.

Obviously, plenty of claims have been made before, so I'm asking --
does this sound on the level?


Water injection has been around for a long time, both for internal
combustion and aircraft jet engines, it does improve efficiency, reduce
temperatures and reduce some emissions. It depends what is being claimed for
the actual device.

Regards
Jeff