Deciding whether to fill your tank before a fuel price hike in South Africa depends on the size of your vehicle’s tank and the magnitude of the expected increase. While filling up before the first Wednesday of the month can offer modest savings, you should weigh the potential rand-value benefit against the inconvenience of long queues at petrol stations and the fuel consumed while waiting.
Understanding South African Petrol Price Adjustments
In South Africa, the retail price of petrol is regulated by the government. Prices are adjusted on the first Wednesday of every month, based on international oil prices and the Rand/US Dollar exchange rate. Because these adjustments are predictable, they often trigger a wave of “panic buying” at service stations on the Tuesday evening before the price change.
The Mathematics of “Filling Up Early”
To determine if it is worth your time, perform a quick calculation: take the projected increase per litre and multiply it by your car’s fuel tank capacity.
- Example: If petrol is set to rise by R1.50 per litre and you have a 50-litre tank, the total potential saving is R75.00.
For many motorists, saving R50 to R100 is not worth the stress of waiting in a long queue, potentially idling in traffic, or dealing with impatient drivers. However, for those with large SUVs, bakkies, or commercial vehicles with massive tanks, the savings can be substantial enough to justify the trip.
Debunking Fuel Myths
You may have heard advice suggesting that you should fill up only in the early morning or late evening when the ground is cooler, under the assumption that the fuel is denser and you get “more” for your money.
Is Morning Refuelling Effective?
While it is scientifically true that fuel becomes denser in colder temperatures, petrol stations in South Africa store their fuel in underground tanks. These tanks are well-insulated and remain at a relatively constant, cool temperature regardless of the time of day or surface heat. Therefore, the density of the fuel being pumped remains virtually unchanged, and the “morning fill-up” strategy is largely a myth with negligible benefits for the average consumer.
The “Slow Flow” Technique
Some drivers believe that filling up on the slowest setting reduces vapour return and ensures more liquid enters the tank. While technically sound in principle, modern fuel pumps are designed to manage flow rates efficiently. The difference in volume gained from using a slow setting is typically too insignificant to make a measurable difference in your monthly budget.
Better Ways to Manage Fuel Costs
Rather than focusing on the timing of a single fill-up, you can achieve more consistent savings by addressing how you drive and maintain your vehicle.
- Improve Driving Habits: Aggressive acceleration and harsh braking can increase fuel consumption by as much as 30%. Driving smoothly and anticipating traffic flow are far more effective for your wallet than timing your fuel stops.
- Maintain Your Vehicle: Underinflated tyres increase rolling resistance, forcing your engine to work harder and burn more fuel. Regular servicing, including cleaning or replacing air filters and spark plugs, ensures your engine runs at peak efficiency.
- Lighten the Load: Remove unnecessary items from your boot or roof racks. Extra weight requires more energy to move, directly impacting your fuel economy, especially in stop-start urban driving.
Frequently Asked Questions
When do petrol prices change in South Africa?
Petrol prices in South Africa are adjusted on the first Wednesday of every month. The new prices are gazetted by the Department of Mineral and Petroleum Resources and apply nationwide from the stroke of midnight.
How do I know if it’s worth waiting in a queue to fill up?
Calculate the potential saving by multiplying the expected price increase per litre by your car’s tank size. If the total saving is less than R50, it is rarely worth the time, effort, and fuel wasted sitting in a long queue at a busy petrol station.
Do petrol stations charge different prices?
The retail price of petrol is regulated by the government, meaning it is the same across the country for specific zones. However, diesel prices are not regulated in the same way, meaning different retailers may offer slightly different prices for diesel.
Does the temperature of the fuel really affect how much I get?
Because petrol in South Africa is stored in underground tanks, it is shielded from surface temperature fluctuations. You will not get significantly more fuel by filling up in the early morning compared to the afternoon.
Why do fuel prices fluctuate so much?
Fuel prices are primarily driven by the “Basic Fuel Price” (BFP), which is determined by the international cost of crude oil and the Rand/US Dollar exchange rate. When the Rand weakens against the Dollar or global oil prices spike, domestic fuel prices inevitably rise.
Should I avoid filling up when a tanker is delivering?
It is generally recommended to avoid filling up while a tanker is offloading fuel into the station’s underground tanks. The delivery process can stir up sediment or impurities that have settled at the bottom of the storage tank, which could potentially end up in your vehicle’s fuel system.