Fuel savers

1st Apr 2013 6:00 pm

Wants to know why all carmakers are not using fuel-saving devices on their cars.


I’ve used an imported fuel-saver device on my Santro car, which gives me 21kpl without AC. I am fully satisfied by its petrol-saving performance. Why aren’t all car manufacturers using this device?

KK Soni, via email

AAA The fuel-saver device you’re talking about works on the principle of electrolysis – splitting water into hydrogen and oxygen and inducing the extra oxygen into the engine to achieve a leaner burn. There are a couple of issues though.

As basic physics states, energy can’t be created or destroyed. It just changes from one form to another. Using this device, you are effectively using electricity to produce the extra oxygen. Now where is this electricity coming from? Your car. Or, more precisely, the electrical system of your car. It works like this – when you increase the electrical load on a car, the alternator’s voltage regulator increases the current in the alternator’s coil, which in turn means that the engine has to provide extra power to spin the alternator. And how does it do this? By burning more fuel, of course.

So effectively, you’d gain very little in terms of mileage. To test out the theory, try removing the device and driving the same way you’d normally do, and we’re sure you’d end up with similar mileage figures.
The other critical issue is the operating principle. A petrol engine is meant to perform optimally and reliably at certain ‘air-fuel’ ratio values. The ideal is 14.7 parts of air to 1 part of fuel. But with the extra oxygen induced by the system, the engine tends to run leaner – like 20 parts of air or so for 1 part of fuel. This means the engine runs hotter, and can cause detonation and pinging (bad stuff!) especially in hot ambient weather conditions or when you demand more performance by putting the pedal to the metal.
So now you know why a manufacturer would never use something like this. They aim to produce a package that would offer bulletproof reliability regardless of operating conditions – weather, usage patterns, driving style and so on.


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