Fuel quality

Fuel quality: the basics

Under the Consumer Guarantees Act, goods that are normally bought for personal use must be of an acceptable quality, "fit for purpose", free of minor defects and safe. These guarantees apply to fuel.

The Fair Trading Act states that companies can't misrepresent the qualities of a product they sell you. So, for example, it’s illegal to sell petrol labelled as Premium Unleaded when it's really Unleaded 91. 

Fuel quality monitoring

Fuel Quality Regulations

Regulations governing important properties of petrol and diesel for protecting consumers and the environment, are Engine Fuel Specifications Regulations 2008 (Regulations).

These regulations describe the most important performance properties of your fuel, such as the octane number. They also specify limits for components that could harm you, your vehicle or the environment. These components include aromatics, lead and sulphur.

Find out more about the fuel industry in New Zealand.

Fuel Quality Monitoring Scheme

Under the national fuel quality monitoring scheme, the Measurement and Product Safety Service (MAPSS), in the Ministry of Consumer Affairs, organises testing of petrol and diesel samples to ensure oil companies are complying with the regulations, approximately 40-50 samples are tested each month.

Testing under the scheme concentrates on the fuel’s most critical properties, such as octane number, benzene level, contaminants, aromatics, water in diesel, and sulphur content.

Using a statistical sampling plan, the scheme takes account of the market share of each oil company and the volume of sales for each region.

Motorists fund the fuel quality monitoring scheme through the petroleum fuels monitoring levy. A small percentage of the levy is used to fund the scheme.

Find out more about the fuel quality monitoring scheme.

What happens if a fuel sample fails the test?

Most fuel samples that are tested do meet New Zealand's quality regulations. The few that don't, generally fall outside the specifications by only a small amount.

When this happens, the oil company that supplied the fuel has to investigate why it happened (to prevent it from happening again) and take appropriate action depending on the circumstances, such as removing the fuel from sale.

Samples usually 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. 

Got a problem with fuel quality?

How can I make a complaint about my fuel?

If you think there's a problem with your fuel, contact the service station or oil company that sold it to you. They will investigate your complaint, possibly test the fuel involved and let you know the result.

Fuel samples may be tested for any of the properties specified in the regulations, depending on your complaint. You can also lay a complaint with the Measurement and Product Safety Service (MAPSS), who will follow it up with the oil company concerned.

Contact us

To make a complaint about fuel quality:

Telephone: 0508 MAPSS INFO (0508 627 774)

International Clients: 00 64 3 962 2580

Or you can email us.