There is no doubt that diesel is the biggest fleet operating cost. In previous newsletters we have expressed our concern about fuel ‘spiking’ or adulteration and recent press reports offer hard proof of this.

The evidence of a wide-spread malpractice in diesel fuel adulteration is found in reported sales of illuminating paraffin (kerosene). Press reports on paraffin data in South Africa points to a two-fold increase in kerosene consumption over the past three years, from 600,000 kilolitres annually to
over 1.2 million kilolitres. Does this mean that the number of consumers using paraffin for cooking and lighting has doubled during this period? That is hardly likely.

In fact, observes a comment in TopAuto, ‘the rise (in kerosene sales) has taken place against the backdrop of an increasing number of people living in poverty, which means we should be seeing a lower demand for this fuel (kerosene).’

This raises the question – where is all this kerosene being used? The answer will be in fuel adulteration which in turn has a technical knock-on effect on diesel engine efficiency and longevity. This will alter the cetane number, flash-point and lubricity of diesel fuel. Exhaust emission controls
are also affected.

Greed drives the system. Kerosene is mixed in to retain margins. It is illegal to engage in this practice and a marker is being added to diesel fuel to track the source of malpractice. There are also field reports that chlorine is being added to destroy kerosene markers, but this has a serious consequence of engine failure.

Driver reports must be heeded and followed up – poor starting, exhaust smoke, and lack of power can all be indicators that fuel quality is suspect needing investigation.

For more details, please contact Tony Dos Reis at 031 713 3111 or