How the petrol vs diesel vs hybrid vs ev works
Last updated 10 November 2026
Electric and hybrid cars usually cost more to buy and less to run. Whether that pays off depends on how far you drive and on the price of fuel and electricity. This tool puts both sides in one table.
How it works
- Fuel cars: litres per 100 km × price per litre.
- Electric cars: kWh per 100 km ÷ (1 − charging loss), times the blended electricity price.
- Total = purchase price + energy cost per month × 12 × years.
- Break-even = extra purchase price ÷ monthly energy saving, against the cheapest car to buy.
Worked example
With the starting figures:
- The cheapest vehicle to buy and run over the period is Diesel car.
- Each vehicle’s energy cost a month: Petrol car R 2 520, Diesel car R 1 898, Hybrid car R 1 620, Electric car R 1 013.
How to read your result
The table shows each vehicle’s energy cost a month and its total over the years you chose, which is the purchase price plus the energy for the whole period. The cheapest is the one with the lowest total.
Where a vehicle costs more to buy but less to run, a note shows how many months of energy savings it takes to cover the extra price, measured against the cheapest vehicle to buy. If a vehicle never saves enough, no break-even is shown.
The chart and the table hold the same figures, so you can use whichever is easier to read.
Comparing litres and kilowatt-hours
Fuel cars use litres per hundred kilometres. Electric cars use kilowatt-hours (kWh) per hundred kilometres. The tool multiplies each by its own price, so the two end up as a rand cost a month.
For electric cars, the energy lost while charging is added on top of what the car uses. The price used is a blend of your home electricity price and the public charging price, weighted by the share you charge at home.
Hybrids are entered as a fuel vehicle with their own, lower, litres per hundred kilometres. The tool does not model how a hybrid splits its work between engine and battery, so use a figure that reflects your driving.
Where the numbers come from
The starting figures are examples, not today’s prices. For a fair comparison, check these inputs:
- Consumption: use real-world figures if you have them, such as from the car’s trip computer or your own fill-ups.
- Fuel prices: petrol and diesel prices change often, so use the current pump price.
- Electricity price: use your own tariff for home charging and the price on the charger for public charging.
- Distance: the more you drive, the more the running cost counts against the purchase price.
What this does not cover
This tool looks at purchase price and energy only. It leaves out insurance, services, tyres, finance interest and resale value, and these can differ a lot between a petrol car and an electric one. It also does not cover the cost of installing a home charger or any battery warranty terms. For the wider picture, use the car ownership cost calculator.
Things to watch
- The fuel and electricity prices are examples. Use current prices, and your own charging mix.
- Consumption figures from manufacturers are lower than most real-world driving.
- Public fast charging is usually much more expensive than charging at home.
For the full cost including insurance and resale, use the car ownership cost calculator. Read the full disclaimer.