How much petrol you really get when you pay for 1 litre


Testing by MyBroadband revealed that petrol stations provide customers with exactly the volume of fuel — or more — than what they pay for.

Following the recent petrol and diesel price increases, we decided to test the accuracy of fuel pumps.

To test the calibration accuracy of individual pumps, MyBroadband purchased one litre of petrol from different filling stations and stored it in a clean jerry can.

We ensured that the can was sealed during transportation to limit evaporation and prevent spills.

The fuel volume was then measured using a graduated cylinder with a ±2.5ml accuracy.

As many fuel pumps only measure two decimal places, it would be fair to allow for ±10ml in the measured volume, as this is the accuracy with which the fuel was dispensed.

All the samples we collected were well within this limit, with the lowest measured volume from an Engen garage — 995ml.

What surprised us were the outliers on the high end. There was one sample from Sasol of 1,017ml and the one from BP at 1,085ml.

Because of this large discrepancy, we re-tested the BP station by buying another litre, and this time measured 1,020ml.

During the second sample, we noticed some fuel dripping from the nozzle even before the pump measurement started. There was some fuel already in the hose, increasing the volume we received.

However, it will not significantly affect a larger fill volume, as it is an absolute error of the volume left in the hose and not a pump calibration error.

Our tests showed that fuel pumps are accurately calibrated, ensuring that you get your money’s worth.

The table below shows the measured volume of all the samples.

Fuel Volume
Filling Station Measured Fuel Percentage Difference from 1l
Engen 995 ml -0.5%
Shell 996 ml -0.4%
Caltex 998 ml -0.2%
Total 1005 ml 0.5%
Sasol 1017 ml 1.7%
BP (2nd test) 1020 ml 2.0%
BP (1st test) 1085 ml 8.5%

Measuring equipment

Now read: South Africans could be paying R200 less per tank of petrol


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