I was reading an article in the latest TDR mag about fuel economy improvement methods, and one comment caught my eye - it was about the effects of timing on improving MPG. It pointed out that merely advancing OEM base timing by about 2 degrees would provide an average 2 MPG or so MPG improvement and ALSO pointed out that the
reason it was set the way it is from the factory is because of the EPA and emissions requirements.
Some have quoted the reasoning that "IF there was a WAY to easily improve a vehicles MPG, SURELY the manufacturers would be all OVER it, and get it into the hands of buyers as a means to sell more vehicles".
Not necessarily so! 
There are MANY conflicting factors involved behind the scenes where alternative energy and improved MPG is concerned - just IMAGINE, if overnight, a method was found using plain water, that would significantly improve MPG, or nearly eliminate world -wide, the need for conventional fossil or vegetable fuels!
Our entire economy - and the economies of the world would be impacted - and in ways not clearly seen - or purely beneficial to the governments and major income generators within those countries!
What happens to our own road taxes and related fuel-based income, if we suddenly were able to power our vehicles with tap water? What radical changes would that demand of vehicle makers to produce both the necessarily modified powerplants and HHO generating systems? What happens to the sprawling network of conventional fuel refining, distribution and service stations? What happens to entire nations, such as those in the middle east, whose ONLY resource is crude oil? Think of the impact on MANY fronts of the stock market.
Sure, on the surface, switching from oil to water for vehicle fuels and heating - both in homes and industry seems like a "win" situation - and actually IS for the *people* of the world - but it has potential impact that FAR exceeds just fuel for cars and trucks - and will NEVER be welcomed or promoted on a wide scale - far too many peripheral issues, and individuals in high places with MUCH to lose.
If it happens, it will only happen as, and after, those same folks are able to put in place methods and controls that keep THEM in places of influence, and at the end of the $$$ flow... Regardless of WHAT it takes to make it happen!
You think they don't read, and have forms of input in as many places as possible where discussions like this are taking place? NO, not necessarily talking "conspiracy theories" - just pointing out there IS a downside to a radical and uncontrolled switch in basic energy sources - and that downside will NOT be welcome by the powerful and wealthy in many smoky back rooms across the world - UNTIL those involved establish ways they can benefit and control it!
Do an Internet search on "HHO generators" - and see what you dig up!
Attention: TDR Forum Junkies 
Could it be that the returns were more than new sales?
