Petrol pumps – frequent questions and complaints

People will complain to us if they think they are getting ripped off at the petrol pump – even if it is over 1p.

In this post I will cover some frequent questions/complaints we receive.

Do fuel pumps have to be colour coded? e.g. green for unleaded and black for diesel.


This question comes up when someone visits a petrol station and accidentally puts in the wrong fuel without reading the writing on the pump. Generally speaking green is for unleaded and black for diesel but some petrol stations use other colours for their premium fuel.

(If you put the wrong fuel in your car, do not start the engine – call someone out to take the fuel out so you can put the correct fuel in. You may have to push your car off the forecourt).

Do fuel stations have to display prices so that they are visible from the road?


In the UK the vast majority of fuel stations have signs up to show how much the fuel costs so drivers can see the price before they drive onto the forecourt. There is no legal requirement to display prices in this way. The retailer just has to ensure the price is clear before the consumer fills up (i.e. putting the price on the pump is sufficient).

When I put the nozzle back on the pump the counter ran up an extra 1p. Am I being ripped off?

I can borrow the answer to this from Hampshire Trading Standards. Unfortunatley they have removed the original webpage which this was on:

Measurement of fuel in a petrol pump involves the pumped fuel causing a ‘pulser’ to rotate and send a signal to a processor (computer). The customer display shows the quantity delivered and the price as calculated by the computer.

Because the price of petrol is now so high, a very small movement in the pulser can be enough to trip the price indication by a penny. In reality, this represents only a very small quantity of petrol – about a teaspoonful in fact. The running on can be caused by simply just passing the precise quantity through normal delivery, or when the nozzle is replaced, the internal volume of the hose can change due to internal pressure forcing more fuel into the hose. This effect is called ‘hose dilation’ and is simply the hose swelling slightly. The error in such cases, if any, is very minor and well inside the permitted pump error tolerances of -0.5% to +1.0%.

Before a pump can be put into use in the UK, it must be granted a Certificate of Approval issued by the National Weights and Measures Laboratory. Part of the Laboratory’s approval process is that they must be satisfied with the method of price computation.

As long as the price of fuel remains high, this phenomenon will continue to happen. There is no cure for the problem, but it may be some reassurance to know that as a customer you are not receiving short measure.

Some garages now have ‘penny boxes’ on the counter where some customers place the odd pennies when their transactions have ‘run on’ and that other customers, who are confrontational about the extra penny, take a penny out. This has been found useful in avoiding problems.

My cars fuel tank is 50 litres according to the manual but I have been able to put in 60 litres of fuel. Am I being ripped off?

A fuel pump that is working properly and within legal limits is very accurate. They can dispense 0.5% less or 1% more than what is requested.

The size given for the fuel tank in the manual is only a guide – so the tank size will be about 50 litres – but there will usually be extra space to allow for the fuel to expand and space for the vapour. There will also be fuel in the pipes.

What this all means is that although your cars manual might say the tank is 50 litres that does not mean your car cannot take more than 50 litres.

Clearly if you normally max out at 50 litres and you visit a station and you have been about to put in 65 litres – that might indicate the fuel pump is not accurately measuring the amount of liquid that is being dispensed but that is not always the case.

I have a petrol can that says it can hold 5 litres. I managed to put 6 litres in. Am I being ripped off?

A fuel pump that is working properly and within legal limits is very accurate. They can dispense 0.5 less or 1% more than what is requested.

A container that holds exactly 5 litres would have to be me made to a high standard – cheap petrol cans are unlikely to be made to hold exactly 5 litres. In fact they will hold more than 5 litres to allow for the fuel to expand and for vapour – you should not be filling them to the brim – the can will normally have a line to indicate the maximum level which should be roughly 5 litres. The line indicates that 5 litres is unlikely to be very accurate so if you need to put in 5.5 litres to get to the lien that in itself would not mean the pump is measuring fuel incorrectly.

If you want to complain to Trading Standards about a fuel station check out my page on contacting Trading Standards. Most Trading Standards will visit fuel stations to test them – although they may not necessarily react to your complaint immediately. If they have a testing regime in place they may just put a note on their system to visit that station as soon as possible (which could be days/weeks away).

Ensure you have the following information so that the complaint can be followed up if necessary:

  • Address of fuel station
  • Date and time of problem
  • Pump number

Trading Standards will prosecute fuel station inaccuracies – here is one such example:

25 Replies to “Petrol pumps – frequent questions and complaints”

  1. “My cars fuel tank is 50 litres according to the manual but I have been able to put in 60 litres of fuel. Am I being ripped off?”
    Totally disagree with the response on this question. It will be impossible to have 20% variation. The fuel tank is not an estimate but accurate calculation of the tank volume. An example; a Mercedes tank volume is 83.01, a two digits fraction. How wrong of the respondant to this question is when manufacturers have troubled themselves to calculate down to 2 digits of their tank volume!!
    Any thing more than the 2% is absolutely a rep off.

    • Maybe but we regularly tested pumps with these types of complaints and the failure rate was not high. People saying their tank hold X and they have put in Y is not a perfect barometer of whether the pump is faulty or not. It may be an indication but it is not 100%.

  2. I always fill up at the same Sainsburys garage, and have just had to have my fuel pump changed due to water in the tank. Sainsburys are denying any liability – who can I raise this with to get this investigated further please?

    • My website gives details on how to report to TS – see relevant page. I doubt TS would investigate the matter in the sense they would be assisting you to get your money back. If you want to claim damages then the onus is likely be on you to prove it and fund a civil case.

      • i am having to take my car to a garage due to diesel from an Asda fuel station in Cardiff. My car has lost power and will go into eco mode with less revs. what can I do and how do I report them. The issue started just after buying the fuel but I need my car for work.

        • You can pursue them via county court for any repair costs (assuming they don’t agree to pay when you complain). The onus is on you to prove you got the wrong fuel so make sure you keep your receipt. Also it is obviously easier to prove if something goes wrong outside of the forecourt.

  3. Who can I contact reference my local petrol station, everytime (many other locals have noticed too) that I buy petrol, the pumps visible sale goes to around 14p -16p before it starts to dispense petrol, this does not happen at other nearby petrol stations. I have questioned it and the stupid answer I kerp getting is I am being charged for the petrol sitting in the pipe. I believe people are getting g over charged and I need to report it but cant find who to contact

    • Your local trading Standards – which will probably require the complaint to be made via Citizens Advice Consumer Service – as explained on my site.

  4. How do you complain about a local petrol stations prices. My local station has put fuel prices up each day regardless off what he paid for it. There must be away of complaining about it. Surely they cannot keep ripping local folk off. Even the Staff complain about the owner….please advise

    • There is no law that controls price of petrol so no one to complain to and no one to do anything about it.

    • Quite simply – they don’t have to. The duty has gone down but that does not mean the same as the retailer having to reduce the price to the consumer – it just means the duty they pay has gone down. I accept however the Chancellor is expecting the reduction in duty to be passed on to consumers.

  5. Are petrol stations required by law to have the same price on the sign as on the pump so their not attracting customers with a price their not selling at.

  6. can anyone explain how the difference between E5 & E10 is15pence per litre.At one time E5 was the norm,now they’ve invented E10,which can destroy your fuel pipes etc.If I start using E10 & have engine problems as a result do I have any redress against the supplier & is anyone standing up for E5 users or are we being ripped off again with no redress

  7. we put £60 of E10 In our car and when we turned it on the petrol count had not risen.
    can pumps still pump and charge if they are empty?

    • You should have physically felt the petrol come through the pipe. If I recall correctly it is the fuel that ‘drives’ the meter so the meter shouldn’t be going up by £60 with no fuel coming through. I would have thought the pump would be closed of pretty sharpish if it was happening to everyone.

  8. Who can I report my local petrol station to? They keep advertising a lower price on the sign to what is on the pump. Today it was 1.41 on the sign and 1.43 on the pump. I told the person on the till and they didn’t do anything to rectify it. This has happened to me. few times now.

    • Check the website of your local TS, you will probably have to report it via the Citizens Advice helpline and it will be passed to the TS where the business is based – so make sure you give the correct address.

  9. How can I report or find information regarding a petrol station allowing people to refuel their cars while a tanker is also making a delivery, I thought the station needed to be closed for fuelling while the tanker makes its delivery as a matter of safety. The employee just replied “other people have done it so it should be ok” they clearly haven’t had the training on taking deliveries.

    • I would contact the petroleum licencing authority – this will probably be the council or the fire service – it can vary across the country.

  10. Hi l fill up at my local garage. l have noticed a change in how much mileageis is on my Vehicle after filling up. So l put 30Lt in every time in my car it says 375 to empt. . l went to another garage filled up put 30 Lt in. When checking my mileage it was 430 to empty. l made sure my car had 100 miles to empty at both garage’s. is the first garage ripping me off

    • The only way to really tell properly would be for Trading Standards to go to the site in question and test using our calibrated 20l fuel cans – these cans will tell us how much fuel is being dispensed when the meter says 20l. What your car says may be a good indication but it wouldn’t be sufficient to prove anything legally – the computer and the fuel tank will be be calibrated Fuel can also be affected by expansion. Most fuel pumps that we find wrong are only out by a small amount at 20l – usually due to wear and tear rather than fraud.

Leave a Reply

Your email address will not be published. Required fields are marked *