Where do the fuel consumption figures used on this site come from?
Most vehicles imported into New Zealand are either new cars or Japanese used cars. Fuel consumption data for new vehicles is obtained using a European test procedure that has also been adopted in Australia.1 Fuel consumption data for used Japanese vehicles is obtained using a Japanese test procedure.
Both procedures involve a standardised test carried out under laboratory conditions where all outside influences, such as driving style, weather, gradient and road condition, are controlled. This allows test results to be compared to other results obtained from tests carried out under the same conditions.
Results from Japanese tests are not comparable to results from European/Australian tests, and vice versa.
About the tests
New vehicle testing is carried out by independent test organisations or by the manufacturers at their own test facilities. The test results are normally part of the vehicle’s official certification in the country in which it is sold.2
Standard tests are not fully representative of real life driving conditions because:
- It is not practical to test every new car. A typical car, of every model from each production run, is chosen for testing.
- Variations in driving styles and in road, car and weather conditions can significantly influence the results achieved.
While you may not have much control over some factors (such as traffic conditions), you do have control over others (such as how you drive and how well your car is maintained). You will find tips on how to minimise fuel consumption on the Habits page.
The tests are carried out on new cars. Some deterioration of fuel consumption occurs to vehicles as they age, depending on how much they are used and maintained. As a guide, an older vehicle will consume more fuel than an equivalent new vehicle.
The European test method
There are two parts to the European fuel consumption test, an urban and an extra-urban cycle. The cars tested have to be run-in; that means they must have been driven for at least 3,000 km before testing.
Urban cycle
The urban test cycle is carried out in a laboratory at an ambient temperature of 20°C to 30°C
on a rolling road from a cold start; ie, the engine has not run for several hours. The cycle
consists of a series of accelerations, steady-speed driving, decelerating and idling. The
maximum speed is 50 km/h, the average speed is 19 km/h and the distance covered is four km.
The urban cycle is repeated four times.
Extra-urban cycle
This cycle is conducted immediately after the urban cycle, and consists of about half
steady-speed driving and the rest accelerations, decelerations and some idling. The maximum
speed is 120 km/h, average speed is 63 km/h and the distance covered is seven km.
Combined fuel consumption figure
The results of the urban and extra-urban cycles are combined and presented as the final
figure. This is arrived at by averaging the two parts of the test and weighting them by the
distances covered in each part.
The European test is illustrated on the chart below.
The Japanese test method
The Japanese 10-15 mode test drive cycle is made up of two separate drive cycles. The 10 mode drive cycle is a low speed urban drive cycle, while the 15 mode cycle is a higher speed extra-urban cycle. The two cycles are combined form the 10-15 mode cycle. As with the European test, it is carried out on a dynamometer under strictly controlled conditions.
10 Mode (urban) cycle
This cycle represents low speed driving in a congested city environment. It is 135 seconds
long and consists of a series of accelerations and decelerations. The maximum speed is 40km/h,
while the average speed is 17.7 km/h.
15 Mode (extra-urban) cycle
This cycle represents higher speed driving in an open road environment. It is 231 seconds long
and consists of a series of accelerations and decelerations at higher speeds than the 10 mode
cycle. The maximum speed is 70 km/hr, while the average speed is 33.88 km/hr.
10-15 Mode (combined) cycle
This cycle starts with an initial 15 mode cycle to warm the engine up (with no emissions
sample collected), followed by a short idle period. The 10 mode cycle is then repeated three
times and is followed by a single 15 mode cycle. The total fuel consumption is measured using
the emissions collected during the three 10 mode and one 15 mode cycles.
The Japanese test is illustrated on the chart below.
What are road user charges?
Users of diesel-powered vehicles contribute towards the cost of the upkeep of New Zealand’s road by paying road user charges (RUC). This is a charge over and above the cost of their diesel fuel. (Other road users pay levies which are included in the price of their fuel at the pump.)
To pay the charges, vehicle owners buy a road user charges licence (RUC licence), based on the type and weight of the vehicle and the distance to be travelled. The RUC licence must be displayed at all times on the inside of the front windscreen on the passenger’s side.
More information on road user charges:
http://www.nzta.govt.nz/resources/factsheets/38/index.html
http://www.nzta.govt.nz/vehicle/registration-licensing/ruc.html
Notes
- UN/ECE Regulation 101, Australian Design Rule 83/01
- New Zealand does not include certified fuel consumption results as part of the formal vehicle approval. The results used in this website are provided by vehicle manufacturers and, while representative of the vehicles sold in New Zealand, are not necessarily independently certified results.
