[charlo49]

i found a wikipedia page on fuel saving devices. it is the usual hatchet job on these devices.

notice this one

Fuel & oil additives[edit]

Compounds sold for addition to the vehicle's fuel may include tin, magnesium and platinum. The claimed purpose of these is generally to improve the energy density of the fuel.[citation needed]

Additives for addition to the engine oil, sometimes marketed as "engine treatments", contain teflon, zinc, or chlorine compounds; none of these is appropriate or helpful when added to an engine's crankcase, and they can in fact damage the engine.[9] The US Federal Trade Commission has aggressively pursued marketers of oil additives falsely claimed to improve fuel economy.[10][11][12][13][14][15]

this is very interesting, when the other wikipedia page says the european manufacturers are allowed to use lubricants not available to the public specifically to improve fuel economy.