Have you ever wondered why your vehicle isn’t matching the MPG figures it claims it can do? In September, the way in which new vehicles’ MPG figures, CO2 levels and pollutant emissions data are obtained changed. Out went the old NEDC test and in came the Worldwide Harmonised Light Vehicle Test Procedure or WLTP for short. WLTP will be based on real-world driving data rather than theoretical driving, meaning the new the test procedure will give much more realistic figures.
When will WLTP come into force?
From the 1st September, all new cars on sale must have undergone the WLTP. Brands such as Volvo and Suzuki anticipated the switch and have been compliant and releasing WLTP figures for some time now. However, some cars that have been discontinued will be allowed to be sold using the old NEDC figures for another year; the Toyota Avensis which was dropped earlier this year is one example of this.
What is the difference between the NEDC test and WLTP test?
|
|
NEDC |
WLTP |
|
Test cycle |
Single test cycle |
Dynamic cycle more representative of real driving |
|
Cycle time |
20 minutes |
30 minutes |
|
Cycle distance |
11km |
23.25km |
|
Driving phases |
2 phases, 66% urban / 34% non-urban |
4 more dynamic phases, 52% urban / 48% non-urban |
|
Average speed |
34kph |
46.5kph |
|
Maximum speed |
120kph |
131kph |
|
Influence of optional equipment |
Impact on CO2 and fuel figures and considered under NEDC |
Additional features (which can differ per car are considered) |
|
Gear shifts |
Vehicles have fixed gear shift points |
Different gear shifts points for each vehicle |
|
Test temperatures |
Measurements at 20-30oC |
Measurements t 23oC, CO2 values corrected at 14oC |
Information taken from https://bit.ly/2xMKGxD - 19/9/18
What does it mean for me?
The main effect WLTP will have is on those who are looking to buy a brand-new car. As every single model, in every trim level and every engine specification must be tested, some manufacturers have halted production to ensure they have the time to get through the tests.
Road tax
Due to the high volume of vehicles going through the WLTP, it’s going to take some time before we see the figures that have been obtained. This is expected to be at least 2020, so there are no plans for tax increases for the time being.
You can check the CO2 emissions and fuel figures of a vehicle by visiting the GOV.UK website.
How will figures vary?
When you are searching online for a new vehicle, you may notice that MPG figures are shown 3 ways; urban, extra urban and combined. These will be changed to low, medium, high, extra high and most importantly combined.