Has anyone ever herd of, or tried this..Its called the Fitch Fuel Catalyst.They claim Fuel treated with the Fitch Fuel Catalyst delivers a myriad of benefits: Improved Fuel Economy (1 - 2.5 mpg)
Increased Octane or Cetane
Improved Performance - Horsepower & Torque
Allows for the use of a Lower Octane (engines requiring 93 can operate on 91, those requiring 91 can operate on 89, & so on)
Reduced Emissions
Reduced number of annual oil changes
Reduced Maintenance (cleaner injectors, carbs, plugs)
They show 2 kinds on their web page,a fuel tank drop in one, and a fuel line, inline one.What do you think,does it work,or is it a gimmik.

 

If it was that simple and effective, GM would have included it with the car.