FUEL-SAVING FARCE

With the current hike in the price of petrol, I am considering purchasing a fuel-saving device. I know how to save fuel by changing my driving style but I need an additional saving. There are several devices in the market and they promise significant results and even list favourable references on their websites. I am a bit sceptical but, in difficult financial times, I am tempted to try one. HENDRIK LOUW Parow

Unfortunately, when the price of fuel increases, there is always a spike in the number of advertisements of fuel-saving devices to entice motorists. CAR magazine conducted scientific testing on a number of these devices for the May 2016 issue (search Fuel-saving devices busted! on Carmag.co.za). In essence, these are all scams to con people out of their money.

It takes only a basic understanding of engineering to realise these devices cannot work. Most of them target the combustion process by altering the airflow or somehow modifying the fuel entering the engine (the usual suspects include magnets, airflow modifiers and even fuel additives). The combustion process in a modern internalcombustion engine is already capable of extracting more than 99% of the energy in the fuel. Therefore, there is very little room for improvement.

Many favourable references are written in good faith (the placebo effect is well documented). Folks purchase a product and expect it to work. Subconsciously, they adapt their driving style and, as a result, there is a sudden drop in fuel consumption (driving style has by far the biggest influence on fuel economy). Given time, old habits return and the “benefit” is lost.

Steer clear of these devices.