
A food shocker is in the pipeline as diesel goes up.
Image: Pezels
When the South African Reserve Bank models inflation risks, it starts with oil prices and the rand.
But for South African households, the real impact is far more immediate – and far more tangible – at the supermarket till.
Governor Lesetja Kganyago said the central bank had modelled two scenarios tied to sustained higher oil prices. In the first, oil averages close to $100 a barrel, and the rand weakens by around 5%, pushing inflation above 4% and requiring an additional interest rate increase this year.
In a more severe scenario, where oil remains above $100 for over a year, and the rand weakens by about 10%, inflation exceeds 5%, and several rate hikes would be required before it returns to target by 2028.
In both cases, growth is weaker initially before there is some catch-up later, Kganyago said. That is the macroeconomic framing. The reality for households sits much closer to home – and it runs through diesel.
The shock
A potential increase of around R11 per litre in diesel from 1 April represents a structural cost shock, not a marginal adjustment.
- Fuel is embedded across the entire food system:
- production through tractors and irrigation
- processing through energy-intensive operations
- logistics through long-distance transport
- retail through backup power and distribution
South Africa’s supply chain is heavily road-based, with roughly 80% of goods transported by truck. That system is overwhelmingly diesel-powered, with millions of commercial vehicles moving goods across the country daily.
Transport alone can account for up to 10% to 15% of the final price of food, depending on distance and product type.
A jump from roughly R25/litre to R36/litre implies a 44% increase in diesel costs.
Even partial pass-through has a measurable impact. Some crude mathematics based just on headline inflation expectations across this piece, with the anticipated fuel price hike, shows that:
- transport channel alone – about 4.4% upward pressure on food prices
- broader system effects – realistically 6% to 10% food inflation
That is before factoring in a weaker rand, which raises the cost of imported inputs like fertiliser and fuel itself.

The flow through effects of higher fuel costs.
Image ChatGPT
