When you buy petrol or diesel, you have rights under the Consumer Guarantees Act (CGA) and the Fair Trading Act (FTA).
The FTA applies so that companies can’t misrepresent the qualities of fuel, eg it’s illegal to sell petrol labelled as Premium Unleaded when it’s really Unleaded 91.
Petrol prices are not regulated by the government, but shop around for the best price when buying fuel. Most service stations have days when fuel is cheaper. Service stations must not make false or misleading claims about their prices under the FTA either.
Under the national fuel quality monitoring scheme, Trading Standards (part of the Ministry of Business, Innovation and Employment) organises testing of petrol and diesel samples to ensure fuel companies are complying with the regulations. Approximately 30–40 samples are tested each month.
Motorists fund the fuel quality monitoring scheme through a small part of the petroleum fuels monitoring levy.
A small number of samples may fail because the fuel has been contaminated somewhere along the distribution chain. For example, some diesel may have mistakenly been put into a service station’s petrol tank.
Accuracy of petrol pumps
Trading Standards appoints Accredited Persons to check that fuel pumps are accurate under the Weights and Measures Act. A certificate of accuracy will be issued and a small adhesive label placed on the pump where you can see it.
While car manufacturers’ stated capacities for fuel tanks are not precise measurements, petrol pumps are calibrated measuring instruments, so they may differ. Also, the design of car fill pipes allows fuel or vapour to sometimes shut off the petrol pump nozzle at an early stage in the fill.
It is safer not to fill the petrol tank right to the top, as petrol will expand – due to the temperature in the car being higher than that in the underground storage tank.
All petrol pumps must be certified accurate.
You should always:
check that the price on the pump matches the price on the sign
make sure that the pump is set to zero before you start
remember the pump number and price so the cashier doesn’t charge you incorrectly
check your receipt.
Although petrol prices are not regulated, petrol stations can’t get together to fix prices so that there is no competition within a local area. Price-fixing is illegal under the Commerce Act(external link).
Citizens Advice Bureau (CAB) — a free, independent service, run by volunteers. CAB can advise you on your consumer rights and obligations, in person, by phone, or online.
Community Law Centre — offers free one-on-one legal advice to people with limited finances. The organisation has 24 community law centres throughout the country. You can find legal information and other resources on its website.
Jack notices all the petrol stations locally are charging exactly the same prices for unleaded petrol for the month of September. He finds this odd and contacts the Commerce Commission to report it. The Commission may choose to investigate whether the petrol stations have got together to fix prices.