The new procedure for consumption and emissions tests – WLTP (Worldwide Harmonized Light-Duty Vehicles Test Procedure) – ensures greater transparency and will gradually replace the NEDC (New European Driving Cycle). The WLTP is mandatory for all EU member states - other countries will look at introducing it at a later date.

WLTP and NEDC explained

The WLTP was introduced on 1 September 2017. This new procedure for consumption and emissions tests is designed to deliver test results that more accurately reflect real driving behaviour than the previous NEDC. Since September 2017, all newly developed vehicles and vehicles with new powertrains have been certified under WLTP. From September 2018, the WLTP will then apply to all other newly registered vehicles. Between now and August 2018, therefore,  smart will certify its passenger car portfolio under WLTP. In the transitional period, vehicles with WLTP and NEDC certification will be simultaneously available. In addition, there will be an NEDC consumption figure that is based on the WLTP and which will also be higher. This figure will be used in sales documents until 2020.

WLTP and NEDC explained

WLTP and NEDC compared

Starting temperature Cold Cold
Cycle duration 1800 s 1180 s
Standstill 242 s 267 s
Stopping time 13,4% 22,6%
Distance 23,262 m 10,931 m
Maximum speed 131.3 km/h 120 km/h
Average speed 46.5 km/h 33.35 km/h
Individual model's optional equipment taken into account for weight, aerodynamics, rolling resistance, on-board electrical system consumption; without air conditioning not taken into account except for tyres; 
without air conditioning
Temperature 23°C 25 +/- 5°C

What does this mean for me as a customer?

The introduction of the WLTP (Worldwide Harmonized Light Vehicle Test Procedure) will ensure greater transparency with regard to fuel consumption. Customers will benefit from the WLTP because it provides a more realistic yardstick for comparing the consumption and emissions figures of different vehicle models. However, the new test conditions will also mean changes in the CO2 and consumption figures. For process-related reasons, technically the same vehicle will have numerically higher CO2 and consumption figures under WLTP than under NEDC (New European Driving Cycle). This is because the new cycle takes account of optional equipment and applies stricter test conditions, for example.

The WLTP delivers accurate figures.

The WLTP delivers accurate figures.

As the WLTP takes each vehicle's particular equipment specification into consideration, its results are more accurate than under the NEDC; they are, as it were, vehicle-specific. This alters nothing in terms of everyday fuel consumption.
From September 2017, a new procedure for consumption and emissions tests is being introduced in the automotive industry; all newly certified vehicle models will be tested under WLTP. At the same time, the NEDC consumption figures will continue to be calculated and shown as the only valid consumption figures in promotional materials.
Between now and September 2018, smart will gradually certify its portfolio under WLTP. From that date, it is likely that the new WLTP figures will be shown in all sales documents and other publications. The NEDC consumption will be shown in the case of discontinued models.

Introduction of the WLTP cycle.

Introduction of the WLTP cycle.

The goal of the WLTP is the global harmonisation of test procedures. It is designed to deliver test results that more accurately reflect real driving behaviour than the NEDC procedure. Used vehicles will not be affected by this changeover and will keep their certified NEDC figures. Until at least the end of 2020, both WLTP and NEDC figures will be calculated for all vehicles. These figures will be included side by side in the vehicle documents with effect from the respective vehicle certification date. From 2021, the measured WLTP figures will be the only consumption and emissions figures for all passenger cars, providing each EU member state has adapted its tax system. The actual test phases of the WLTP are abbreviated to WLTC which, in turn, is divided into three classes. Almost every passenger car will be tested under WLTC Class 3 (Worldwide Harmonized Light-Duty Vehicles Test Cycle), which covers all passenger cars with a power/weight ratio of more than 34 kW/t (46 hp/t kerb weight).

WLTP: Greater transparency.

WLTP: Greater transparency.

The WLTP provides smart customers with vehicle-specific consumption figures that are more realistic and more transparent. While cross-manufacturer and cross-model comparability is retained, the measured consumption figures are a more accurate reflection of everyday driving and take more factors into consideration than the NEDC. smart is an advocate of both new, more realistic laboratory testing and on-road measurements. This ensures greater clarity, transparency and certainty for smart customers. The introduction of WLTP and RDE (Real Driving Emissions) represents an important step in this direction.

What does this mean for customers?

What does this mean for customers?

In future, when choosing their optional equipment, customers will be able to calculate the CO2 emissions of their vehicle model more accurately than before. To ensure clarity and maximum possible transparency, smart will actively follow the introduction phases of the WLTP and provide dealers and customers with targeted information. This will also include a new form of information based on equipment specification: from the model with the lowest energy consumption to the version with the highest energy consumption. Numerically, the spread will extend from "WLTP Low" (minimum optional equipment) to "WLTP High" (maximum optional equipment).

How to request your RDE results.

How to request your RDE results.

Find out about emissions from your vehicle under true-life conditions.

Find out about emissions from your vehicle under true-life conditions.
The term Real Driving Emissions (RDE) denotes the true-life emissions output from cars, trucks and buses in everyday usage. Exhaust gas measurement for the purposes of type approval used to be performed exclusively on  dynamometers. When the RDE (EU) 427/2016 legislation came into force in March 2016, it also became necessary to measure emissions under true-life driving conditions within defined parameters. Together with the RDE limits for true-life driving conditions in force  since September 2017, this is an important step towards a cleaner and lower-emission automotive future.

You can request the RDE results of our smart vehicles, compiled both by us as the manufacturer and by independent, state-certified technical services, by indicating the PEMS test family of your smart vehicle using the following form. 

Frequently asked questions.

What is WLTP?

The abbreviation WLTP stands for Worldwide Harmonized Light-Duty Vehicle Test Procedure and is a test procedure that measures a vehicle's consumption and emissions figures on a chassis dynamometer. From 1 September 2017, the WLTP will be gradually introduced,replacing the previous NEDC test procedure.

Thanks to its dynamic bias, the WLTP is significantly more realistic in terms of actual driving behaviour. The WLTP is characterised by significantly higher acceleration events and by a considerably more dynamic driving profile. The top speed is increased to  131 km/h, with the average speed rising to 47 km/h.

The driving time is  10 minutes longer, along with a higher proportion of motorway journeys simulated on the dynamometer; at the same time, the proportion of stopping times is reduced. The driven distance is doubled to 23 kilometres.

The shift points are calculated in advance and are specific to the vehicle and its powertrain. All optional equipment with an influence on vehicle aerodynamics, rolling resistance and vehicle mass will in future be factored into the measurement. The power consumption of comfort/convenience functions will likewise lead to a higher CO2 figure. The only exception in the first stage of the WLTP is the air conditioning.

With the WLTP, the goal is to introduce a globally binding standard, with EU countries taking the lead. This will help to compare the fuel consumption and pollutant emissions of vehicles from different manufacturers. In addition, the standards will help to enable authorities to verify compliance with the statutory emissions limits – from hydrocarbons (HC) and carbon monoxide (CO) to nitrogen oxides (NOx) and particulates.

What is WLTC?

The driving cycles of the WLTP are known as WLTC – Worldwide Harmonized Light-Duty Vehicles Test Cycle. For different vehicle classes, the WLTP has three different driving cycles that take the particular  power/weight ratio into consideration. The majority of passenger cars registered in the EU will be assigned to WLTC Class 3, which covers a power/weight ratio of more than 34 kW/t (46 hp/t). The test cycle for Class 3 vehicles consists of four parts – Low, Medium, High, Extra High. These simulate urban and extra-urban driving as well as driving on highways and motorways.

What is NEDC?

The NEDC (New European Driving Cycle) is the currently valid test cycle for passenger cars. The first European driving cycle came into effect in 1970 with the goal of providing customers with comparable and reproducible figures across all manufacturers. In 1992, the NEDC was extended beyond urban traffic. At 34 km/h, the average speed in the NEDC is low, as are the acceleration events and maximum speed of 120 km/h. The composition of the cycle is no longer consistent with today's average distribution of distances driven on different types of roads.

The measurement takes account of neither aerodynamics and weight nor the energy consumption of optional equipment and comfort/convenience functions such as the air conditioning, radio and seat heating. Added to this are technological parameters that promote discrepancies.

For instance, start/stop technology has a relatively high influence in the NEDC, as the NEDC has a high proportion of stopping times. In the case of vehicles with manual transmission, vehicle-specific parameters are not taken into consideration when the shift points are calculated.

This can lead to significant discrepancies in consumption in comparison with real driving conditions. Continual technological advances mean that the NEDC is no longer up to date.

What is RDE?

RDE stands for Real Driving Emissions and is a road test for determining pollutant emissions. It describes a vehicle's emissions under real on-road conditions. To date, exhaust emissions measurements for type approval have taken place exclusively on dynamometers. With effect from March 2016, emissions must also be measured within a defined framework under real driving conditions. A PEMS (Portable Emissions Measurement System) is used to measure Nitrogen oxide (NOx) and carbon monoxide (CO) emissions. At a later date,  particulate emissions will also be measured. There is no set cycle; driving and measuring take place in real everyday traffic in compliance with road traffic regulations. The vehicles are driven on public roads for between 90 and 120 minutes, one third each on urban and extra-urban roads and on the motorway. An average speed of between 15 and 30 km/h is specified for city driving, while the speed on motorways is 90 and at least 110, but not higher than 145 km/h. The outside temperature must be between 0 and 30 °C , with the air conditioning switched on.

The road test must not take place at over 700 metres above sea level and can have an altitude difference of no more than 100 metres. Since September 2017, compliance with the  Euro 6 emissions limits  has been compulsory in the RDE road tests. In the first stage, compliance has been compulsory since 1 September 2017 for newly certified models, and from 1 September 2019 at the latest compliance will be mandatory for all models.