You may have heard of some changes which are coming into force for new cars from September 2018.

The changes won't affect you, but come on the back of the VW emissions scandal which erupted in September 2015 and are designed to give buyers more confidence. The change will mean that all new cars WILL and MUST be measured for MPG and CO2.

Below is our fast guide which includes all you need to know about WLTP.

WHAT IS WLTP?

So let’s start with what the acronym stands for: Worldwide Harmonised Light Vehicle Test Procedure.

WLTP is a new laboratory test used to measure fuel consumption and CO2 emissions from passenger cars, as well as their pollutant emissions. The new test will give motorists a better idea of the fuel consumption and range of new cars (both internal combustion and electric).

It replaces the current NEDC (New European Driving Cycle) test which has prevailed since the 1990s and has become outdated through both evolutions in driving conditions and technology.

WHAT DOES THIS MEAN FOR ME?

In our opinion, this move will be extremely positive for customers as there will be more accuracy than ever before.

Fuel Consumption

A car or van's fuel consumption performance will not change with new WLTP values. The higher CO2 value does not mean increased fuel consumption, but rather a more realistic CO2 value due to the change in how the vehicles are tested.

Vehicle Taxing

The move to the new WLTP test should not negatively impact vehicle taxation by increasing costs for the consumers. After all, the vehicle’s performance is not affected by the transition to WLTP.

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THE DIFFERENCE BETWEEN THE OLD TEST & NEW TEST

HOW DOES IT WORK?

The new test procedure will apply to all new car registrations from September 2018 and must be certified according to the WLTP test procedure, and no longer on NEDC.

The WLTP driving cycle is divided into four parts with different average speeds. Each part contains a variety of driving phases, stops, acceleration and braking phases. For a certain car type, each powertrain configuration is tested with WLTP for the car’s lightest (most economical) and heaviest (least economical) version.

WLTP was developed with the aim of being used as a global test cycle across different world regions, however whilst WLTP has a common global ‘core’, the European Union and other regions will apply the test in different ways depending on their road traffic laws and needs.

NEDC VS. WLTP

NEDCWLTP
Test CycleSingle testDynamic cycle
Cycle Time20 minutes30 minutes
Cycle Distance11 kilometres23.25 kilometres
Driving Phases2 phases, 66% urban and 34% non-urban driving4 more dynamic phases, 52% urban and 48% non-urban
Average Speed34 kilometre per hour46.5 kilometre per hour
Maximum Speed120 kilometre per hour131 kilometre per hour
Influence of optional equipmentImpact on CO2 and fuel performance not considered under NEDCAdditional features (which can differ per car) are taken into account
Gear ShiftsVehicles have fixed gear shift pointsDifferent gear shift points for each vehicle
Test TemperaturesMeasurements at 20-30°CMeasurements at 23°C, CO2 values corrected to 14°C

WHO IS AFFECTED?

The move to WLTP has had significant impact for car manufacturers. The new regime effectively requires costly and time-consuming testing as follows:

  • all models
  • all engine configurations for all fuel types
  • all trim levels
  • all options including all tyre and wheel combinations
Wltp-diagram-1050x420-1-nov-2018

More details of the new changes to WLTP:

  • The temperature in the testing chamber is 23°C
  • The distance is 23 km
  • The cycle takes 30 minutes
  • It consists of four phases (low, medium, high, extra-high)
  • The average speed is approximately 47 km/h
  • The idle proportion is 13%
  • The maximum speed is above 130 km/h
  • The switching points are calculated individually in advance for each vehicle
  • The vehicle weight and additional equipment are factored into the analysis
  • All possible engine and transmission combinations are measured

Also, there is one other acronym, RDE - which stands for Real Driving Emissions test. A year later, in September 2019, all cars on sale will have to go through a further test, the Real Driving Emissions (RDE). It’s an ‘on the road’ test that pairs with WLTP. In the future, tax bands will rest on WLTP and RDE put together.

If you have any further questions, don't hesitate to get in touch with a member of our team.