Fuel saving devices – what works and what does not!

There are a number of fuel saving devices available in the market. But their efficacy is suspect. In many cases, such devices turn out to be nothing but snake oil – in other words, hoaxes that really do nothing to improve your fuel efficiency.

Here’s a look at some fuel saving devices, with pointers as to whether they work or they don’t. Also read: Hypermiling techniques – how to get maximum mileage from your car

Fuel Saving Tablets

There are number of “fuel saving tablets” available online and at some car accessory shops too. These fuel saving tablets claim to have been made with chemicals from a “special plant” – which means they are biologically derived! In India too, there are at least three brands available online, selling fuel saving tablets. These tablets claim to increase mileage from anywhere between 15% and 27%.

Do they work? No.

Tests by many foreign car magazines such as Popular Mechanics and Car and Driver have shown that these tablets do nothing to improve the fuel efficiency of either petrol or diesel cars. We would not recommend putting any suspicious solid material into your fuel tank – it could just mess with the fuel filter and cause trouble.

Magnetic fuel savers

Magnetic fuel savers are widely marketed for cars and bikes. These devices consist of small magnets that are housed in a plastic shell and clip on over your car or bikes fuel line. What these magnets claim to do is to “energise the fuel” by magnetising the molecules in the petrol or diesel “so that they flow in an even pattern” leading to better combustion! The marketers for these “fuel savers” claim a 27% increase in petrol mileage (which means a car that gave 10 kmpl should now give 12.7 kmpl) or a 33% increase in LPG mileage (some of these are also sold to gullible housewives to save cooking gas).

Do they work? No.

Magnets act on metallic objects or on components that have a magnetic field associated with them. These fuel savers claim to ionize, polarize fuel molecules – something that has not been scientifically proven. In the US, in fact, some marketers of these magnetic fuel savers have been prosecuted for fraud.

(The author has also fallen for this hoax many years ago. A Fucon fuel saver magnet attached to the fuel line of a Wagon-R did nothing to increase fuel efficiency. Avoid.)

Fuel Additives

There are a number of fuel system additives that are available in the market from brands such as STP, Iftek System G and System D, Valvoline, Abro, Bardahl etc. These additives are available separately for petrol and diesel vehicles, and some are also available as engine oil additives too. The fuel system additives that have to be added to the fuel tank claim to clear sludge, clean injectors, improve combustion and reduce emissions.

Do they work? Mostly yes.

However, all these additives work in different ways. For instance, octane boosters, work by improving the octane rating in petrol by up to 3 RON more. These use chemicals such as methylcyclopentadienyl manganese tricarbonyl or tetra ethyl lead to improve the octane rating – chemicals that are also used in the fuel refining process. Then there are injector cleaners, which contain petroleum distillates to clean choked injectors and fuel pumps – these are effective only on partly blocked injectors, and better as a preventive measure, to prevent dirt build up in the first place.

Also read: How to get maximum mileage from your DIESEL car
Also read: How to get maximum mileage from your PETROL car

Share any other experiences you have had with fuel saving devices in the comments.