South Africa’s diesel price increase could deepen again in May, with early Central Energy Fund data indicating a rise of more than R10 per litre if tensions linked to the Strait of Hormuz do not ease. Petrol is also under pressure, with early indications pointing to an increase of about R3 per litre.

The warning comes just days after April’s official fuel price changes took effect. Government said last week that global crude prices, higher shipping costs and a weaker rand all drove the latest increases, even after a temporary reduction in the general fuel levy.

Early CEF data points to another sharp rise

According to the provided IOL report, early-month CEF figures show diesel under-recoveries severe enough to support an increase of more than R10/litre in May. The same report says petrol under-recoveries were sitting between R4.29 and R4.69/litre on a month-average basis, although daily data was lower and could still change before month-end.

That means the South Africa diesel price increase is still provisional, not final. Fuel prices are only adjusted once a month, while oil trades daily, so the outlook can shift before the next official adjustment.

Why fuel prices are rising again

The Department of Mineral and Petroleum Resources said the April 2026 fuel adjustment was driven by a jump in the average Brent crude price from $69.08 to $93.67 during the review period. It also said international product prices added R5.26/litre to petrol and R9.49/litre to diesel in the Basic Fuel Price calculation, while higher shipping costs were linked to conflict in the Middle East.

National Treasury and the mineral resources department said the general fuel levy was cut by R3/litre from 1 April to 5 May 2026, reducing the levy on petrol to R1.10/litre and on diesel to R0.93/litre for that period.

Responses and wider market reaction

The provided source says Brent crude was trading near $111 on Tuesday morning. Separately, AP reported on 7 April that the confrontation involving Iran and the Strait of Hormuz had pushed oil above $108 a barrel, underscoring how quickly global supply fears can feed into South Africa’s fuel price outlook.

For now, motorists and freight operators face another month of uncertainty. Unless oil prices retreat materially before the review period closes, the South Africa diesel price increase could put renewed pressure on transport, food costs and business operating expenses in May.