Biofuel and environmentally friendly cars

Biofuel is a renewable fuel typically made from food crops, used cooking oil, wood waste, or in New Zealand from dairy industry by-products. Biofuel can either be petrol blended with a maximum of 10% bioethanol, or diesel blended with a maximum 5% biodiesel.

Biofuel benefits the environment because it burns more cleanly and reduces the amount of carbon dioxide (greenhouse gas emissions) produced by your car.

How biofuel stacks up

If you use 30 litres of biofuel a week you will save over 250 kilograms of carbon dioxide emissions every year. Biofuel is better suited to newer vehicles however many older vehicles can use it too. Contact your vehicle manufacturer before using biofuel.

While ethanol contains less energy than normal petrol, any increase in the fuel economy of your vehicle using ethanol-blended petrol should be minimal.

However bio-ethanol does contain more oxygen so your fuel will burn better and performance may be improved.

Bioethanol has 30% less energy content than fossil (mineral) fuel, which means you consume about 3% more fuel with a 10% bioethanol blend. However, bioethanol does contain more oxygen so your fuel will burn better and performance may be improved.

Power sources

A new generation of more environmentally friendly vehicles are being designed to run on a number of different power sources; anything from bioethanol to biodiesel and hydrogen. Here's a simple overview of some more established alternatives to mineral fuel.

Hydrogen-powered

Plain old water is the only emission from hydrogen-powered cars. However, producing hydrogen remains expensive and finding renewable energy sources so that its production is also emissions-free is a challenge. These issues continue to hamper technology developments and have slowed the rollout of hydrogen technology and infrastructure.

Hybrids

Hybrid vehicles use two types of power sources; a petrol engine and an electric motor - which maximises the benefits of both.

Hybrid vehicles typically use one of two types of hybrid systems: the series hybrid or the parallel hybrid. Hybrids that use a series drivetrain only receive mechanical power from the electric motor, which is run by either a battery or a gasoline-powered generator. In hybrids with a parallel drivetrain, the electric motor and internal combustion engine can provide mechanical power simultaneously.

Biodiesel

Biodiesel production has been experimented with in New Zealand, made from vegetable oils or tallow (a byproduct of the meat industry).

The New Zealand Engine Fuel Specifications permit mineral diesel to be blended with up to 5% biodiesel for retail sale, without the fuel needing to be labelled as biofuel. That means there is no need for you to make any modifications or other changes to your engine, or undergo any changes to your vehicle's maintenance schedules. However, currently there is no commercially-produced biodiesel retailed in New Zealand.

Bioethanol

Bioethanol is a renewable fuel made by fermenting and distilling products containing sugars and starches. In New Zealand bioethanol is currently made from dairy industry byproducts, and is blended to a maximum 10% with petrol. Bioethanol fuel blends have been used in Europe, Australia and North and South America, for many years.

Currently only Gull sells a bioethanol in New Zealand, with 10% bioethanol blended into their 98 octane petrol.

LPG

Any petrol engine can be converted to run on LPG (liquefied petroleum gas), but although it may cost you less at the pump, the conversion can be pricey and you may lose precious boot space to the second fuel tank needed. Also, the availability of refilling stations is very limited.

New vehicles

You should always check with the manufacturer of your vehicle to ensure it can be fueled with a biofuel.

Used vehicles

For the vast majority of Japanese used imports, vehicle manufacturers state that they can safely use ethanol-blend fuel up to a 3% maximum (E3). Some later models (2006 onwards) may be suitable for ethanol-blend fuel of up to 10%. If your car is fitted with a carburettor then it's highly unlikely to be able to use E3 or E10.

You may also find further information about your car's compatibility with biofuel in the owner's handbook or on the car manufacturer's website.

Caution on using biofuel in boats and other machinery

The AA advises against using biodiesel in recreational boats due to the associated higher risk of diesel bug.

Ethanol blended fuel shouldn't be used for marine and aviation purposes.

You should contact manufacturers prior to using ethanol-blended fuel for small machinery such as motor mowers, chainsaws and generators.

Please contact your manufacturer if you're uncertain whether to use biofuel.