Warning for anyone buying diesel in South Africa

Motorists have been warned about an increase in adulterated diesel circulating in South Africa, following October’s massive fuel price hikes.

This comes after a suspected illicit fuel operation was discovered on a farm outside of Potchefstroom in the North West.

The operation, which was discovered by the South African Revenue Service (SARS) and Bidvest Protea Coin, allegedly used a crude “wash plant” to remove chemical markers from illuminating paraffin.

Investigators said the process was likely meant to remove the markers before the paraffin went into South Africa’s illicit fuel supply chain, where it would be added to diesel.

Waal de Waal, Bidvest Protea Coin chief operating officer, said the crackdown was the result of months of intelligence gathering and monitoring.

“We do the intelligence, and once we confirm it, we get law enforcement involved,” De Waal said.

“Mixing and blending have been around for years, but on a very small scale. But now these days it’s just getting out of hand.”

Diesel adulteration is a growing problem in South Africa, referring to a practice where paraffin and other cheaper substances are blended with diesel to dilute the final product.

Unscrupulous forecourt owners will then sell this adulterated fuel to unsuspecting customers at full price while pocketing the difference.

One factor that makes this possible is the large tax difference between illuminating paraffin and diesel. Since paraffin is not subject to the same fuel levies, it creates an opportunity for criminals to increase diesel volumes and boost their margins.

At the same time, diesel, unlike petrol, is unregulated in South Africa, meaning station owners are free to set their own margins. Since there is no set price for diesel, price differences between forecourts are less likely to draw suspicion.

Additionally, this creates an incentive for station owners to dilute their diesel and sell it at a lower price to undercut their competitors.

De Waal said Bidvest had identified over 100 suspected illicit fuel depots across multiple provinces, with helicopter surveillance teams helping to identify new sites in recent months.

An investigation in 2023 uncovered 70 forecourts across the country that were selling adulterated or “dirty” diesel.

The names of the stations were not made public, though the vast majority were reportedly small, privately owned forecourts and not major chains.

In June 2025, a joint operation by the SAPS and SARS led to several arrests and the seizure of 2 million litres of adulterated fuel, reported BusinessTech.

Some tanks contained diesel stores that turned out to be 68% paraffin. The operation discovered 23 targets across KwaZulu-Natal, Gauteng, and Mpumalanga.

The sting operation led to the detention of 953,515 litres of dirty diesel and the seizure of assets valued at R367.3 million.

Investigators also found two “washrooms,” including a mobile unit allegedly used to remove paraffin markers.

Additionally, 12 fuel transport vehicles were identified in connection with suspected false import declarations, and 13 criminal cases were opened with the SAPS.

Under-declaration was also identified as a tactic in the illicit diesel trade, with some importers declaring shipments of 40,000 litres or less, when in reality they were bringing in over 60,000 litres.

A problem that’s going to get worse with South Africa’s record-high fuel prices

On Wednesday, 7 October 2026, South Africa experienced substantial fuel price hikes, with petrol 95 increasing by R3.33 per litre and diesel 0.005% increasing by R3.58 per litre.

This month, the wholesale price of diesel is sitting at between R31.95 and R33.29 per litre at inland rates.

These high prices are likely to exacerbate the adulterated fuel problems in South Africa, as criminals will try to take advantage of consumer desperation to find cheaper fuel.

Mineral and Petroleum Resources Minister Gwede Mantashe said the illicit fuel trade is a major issue and that the government could not tackle it alone.

“Government continues to work closely with law enforcement agencies to combat this illicit trade. However, we cannot succeed alone,” he said.

“Industry cooperation remains essential in identifying offenders and strengthening compliance throughout the value chain.”

Adulterated diesel can cause serious problems to a vehicle’s engine, as clean diesel contains lubricants that protect the various components.

Diesel that has been diluted with paraffin will not adequately lubricate these systems, leading to rapid wear-and-tear.

It also doesn’t combust properly, which can result in engine knocking, a loss of power, and even engine pre-ignition.