The Low Carbon Vehicle Partnership (LowCVP) has launched a free information portal to give clarity on the new WLTP fuel economy test.

As of today, cars will begin to be tested in a completely new way, allowing buyers to view mpg figures and help them select the car best suited to them.

The new test is called the World Harmonised Light Vehicle Test Procedure (WLTP).

Every new car model will be tested against WLTP starting from today, and by September 2018 all new cars on sale will have WLTP test information.

Importantly, the new WLTP test will become the only truly comparable measure across every car and manufacturer, which is verified by governments and certification bodies.

This data should not be confused or compared with other road tests or ‘real world’ indices.

While WLTP tests are conducted in a laboratory to ensure accuracy and repeatability, they will introduce much more representative testing conditions based on data from ‘real driving’ for new cars and will provide a more accurate basis for measuring emissions and calculating a car’s fuel consumption.

This will provide consumers with much more comprehensive and representative car performance data.

The new test involves a significant number of key changes compared to the ‘old’ NEDC test. 

The new test also places more emphasis on the detailed vehicle specification than the old test, when determining fuel consumption and CO2 emissions.

The recognition of factors such as the mass and aerodynamics of the vehicle, the rolling resistance of the tyres and the impact of options fitted to the car by the manufacturer is greatly improved, to give a more accurate set of values for an individual vehicle.

Most cars tested under WLTP are likely to show higher CO2 emissions and lower fuel economy figures than the same car tested under the old NEDC test.

This reflects much more accurately day-to-day driving, however the actual on-road consumption is completely unaffected by the test type.

Low Carbon Vehicle Partnership’s managing director Andy Eastlake said: “The figures from the new WLTP test are designed to really help consumers understand which powertrain technology and vehicle is best suited to their driving and journey patterns.

“The LowCVP is working with its stakeholder community to coordinate detailed guidance and the presentation of the new data and to maximise the benefit for motorists, to further encourage the uptake of low emission vehicles.”