Fuel saving devices

Fuel saving devices

Since the development of the internal combustion engine, people have looked for ways to increase its efficiency, in order to increase the fuel economy of the automobile.

Although many technologies have had a beneficial effect on vehicles' fuel economies, claims as to the efficacy of some devices have clearly been bogus or misleading.

An early example of a "fuel saving gadget" sold with claims that were difficult to justify is the 200 mpg carburettor designed by Canadian inventor Charles Nelson Pogue.

A good thing to keep in mind when examining fuel saving devices is that most of these claim major increases in combustion efficiency, something that sounds attractive when you consider the average gasoline engine rarely exceeds 35% efficiency. However, the weak point of the engine is not converting the fuel into heat, but the heat into mechanical energy, hence the reason why many fuel saving devices don't work as claimed. On modern engines there is relatively little scope for improving combustion efficiency. Most of what can be legitimately achieved is done by reducing parasitic losses of accessories e.g. fans, water pump, and pumping losses by taller vehicle gearing.

One reason that ineffective fuel saving gadgets have had some success in the marketplace is that it is surprisingly difficult to measure the fuel economy of a vehicle. This is because of the high level of variance in the fuel economy of a vehicle under normal driving conditions. Consequently, it is extremely difficult to measure small changes to fuel economy.

The large degree of fuel economy variance means that due to psychological factors of selective perception, consumers can be mislead as to the effectiveness of a device.

For this reason, regulatory bodies have developed standardised drive cycles that are useful for statistically significant comparisons of fuel economy.

source: http://en.wikipedia.org/wiki/Fuel_saving_devices

Fuel saving devices