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NEDC vs WLTP - Navigating Emission Standards in the EU Used Car Market

Everything used car dealers need to know about NEDC and WLTP procedures for measuring CO2 values to verify compliance with EU emission regulations.

Used cars dealers in the EU need to pay extra attention to the CO2 values of their stock. Strict regulations on emissions and country-specific rules may give you some non-pleasant tax surprises as your car reaches its destination.

One particularly complex issue are the testing procedures used for measuring CO2 emissions in cars, the old NEDC and the new WLTP, which often confuse buyers as either one (or sometimes both) can appear in your car’s documentation.

In this article, we’ll explain the meaning and process behind both of these testing procedures and provide you with tips on finding and reading the correct CO2 values of the cars you’re sourcing for your customers.

Let’s start with some facts about contemporary emission standards in the EU.

Understanding EU Emission Standards

As you already know, the EU has been very serious about cutting CO2 emissions for many years to mitigate the effects of this greenhouse gas on our climate. This effort can be seen across all sectors of life and industry in the EU, through legislature, policies, and regulations, but it’s perhaps most visible in the sector of transportation and the automotive industry.

It’s easy to understand why. According to the European commission, light commercial vehicles (the common name for cars and vans when mentioned together) are responsible for 14.5% of all CO2 emissions produced in the EU.

Illustration: eCarsTrade / Data: European Comission


In order to limit these high figures, EU legislators set limits on how much CO2 cars and vans can emit, expressed as grams of CO2 per driving kilometer (g/km). 

One thing that’s important to mention here is that these targets are not static. Rather, they’re calibrated every couple of years to further limit emissions, until we reach the end-goal of zero emissions. That’s set to happen in 2035, by the way.

However, this only applies to newly produced cars. If you’re buying a used car (for resale or your own use), your vehicle would need to be compliant with the emissions target of its model year. 

And how do you know if your car is compliant? Well, in a properly conducted sale, your car will come with a Certificate of Conformity (COC) issued by the car manufacturer at the time of production.

But how does the car manufacturer arrive at the exact quantity of emissions (grams of CO2 per kilometer) for this specific model? Well, they use testing procedures. 

And that’s where things get a bit complicated. There are two distinct testing procedures, one older and one newer, and both can appear among your purchased car’s documentation, but only one may be taken into consideration during registration and taxation procedures.

NEDC and WLTP: Two Key CO2 Testing Procedures

When assessing CO2 emissions (along with fuel consumption and pollutant emissions), car manufacturers have relied on two testing procedures: NEDC (New European Driving Cycle) and WLTP (Worldwide Harmonized Light Vehicles Test Procedure).

The NEDC is the older of the two. It was devised in the 1980’s and relied on theoretical or lab-setting driving conditions. Because of this testing environment, the NEDC didn’t reflect the CO2 figures emitted during real-life driving conditions. 

As the EU was becoming more strict about cutting pollution created in transportation, there was a need to replace this outdated system with a new testing procedure.

And so, the WLTP was created and implemented for all new cars manufactured from September 2017 onwards. Starting in September 2018, all new cars sold in the EU needed to be compliant with CO2 emissions targets for their model year, under the WLTP testing procedure.

So how is the WLTP procedure different from NEDC? 

The WLTP procedure tests cars in an environment that more closely resembles real driving conditions. Here is a comparison for better understanding.

Illustration: eCarsTrade / Data: Riverale


Another key difference is that under NEDC, emission standards were general. In other words, there was one standard for cars and one for vans in each period. Now, with the arrival of the WLTP, every new car make and model is given a specific CO2 emissions standard to adhere to. These standards are outlined in a special document issued by the European Commission.

As you’re probably already guessing, these two tests, being so different, produce a discrepancy in readings. 

The WLTP, as a rule, records significantly higher CO2 readings compared to NEDC. According to studies, that discrepancy is as high as 9.6g of CO2/km

What does that mean in practical terms? It means that vehicles that were compliant with CO2 emission standards under NEDC can fall short when tested under WLTP conditions. And that’s where the complexities start.

Is the used car you're buying certified under NEDC or WLTP? Can you remain CO2 emission standard compliant if you only have NEDC certification? What are the consequences if you’ve bought a car that isn’t compliant in the country you will be selling it in? Find the answers to these questions in the following sections. 


Which Values Are Relevant According to Vehicle Production and Registration Year?

As we mentioned in the previous sections, the switch from NEDC to WLTP as the testing procedure used to confirm light commercial vehicles adhere to European CO2 emission standards occurred in 2017.

Does that mean that all cars now need to be WLTP certified to comply with emission standards? Actually, no. 

Since this change was implemented in September 2017, it’s only all new cars from that point onward that need to be compliant with this new standard on the side of car manufacturers. And since the change was introduced gradually, on the buyers side, WLTP mostly applies for new cars registrations from September 2018. 

In other words, if the car you’re buying was first registered in September 2018 or later, it must be CO2 compliant under the WLTP testing procedure. 

On the other hand, if the car was registered before this date, your Certificate of Conformity with NEDC CO2 values will apply and you don’t have to do anything to get the car re-certified.

There’s exceptions, though. Remember how we said that the WLTP came into force in September 2018 but became mandatory for car registrations after September 2018? 

Cars registered in the period in between came with both NEDC and WLTP values in some countries and both were admissible. In fact, cars registered after that date can also come with both values expressed, but in most of those cases only the WLTP value is considered. If the car is only NEDC compliant, higher taxes and driving limitations may be imposed.

However, some countries continued to accept NEDC values even after this transition period expired and until as recently as 2021. That’s why it’s crucial to ensure the cars you’re buying are compliant in the country of resale as they are in their country of origin.

All of this can seem a bit confusing, but the point is actually simple. If you need to check whether the car you’re buying is CO2 compliant, you need to know which year it was registered in and what it’s CO2 values are. 

For cars registered before September 2017, you’ll be looking at the NEDC value. If the car was registered after September 2018, as a rule with some exceptions, only the WLTP value is admissible. And if the car was first registered in the period in between, both values will be admissible.

All of this notwithstanding, there are some country-specific rules you need to take into consideration. We’ll look at those next.


Country-Specific Regulations on Acceptable Emissions Certification

The shift from NEDC to WLTP was by no means easy to implement across the European Union. As a result, some implementation differences emerged that made NEDC inadmissible earlier or prolonged the period in which both NEDC and WLTP CO2 values were accepted.

Here’s a brief overview of some of these situations.

► Transitional Periods 

As we already mentioned, some countries have had transitional periods during which a mix of NEDC and WLTP values were accepted. 

This transition period allowed for a smoother shift from the old testing procedure to the new one. This is a common scenario in used car sales where a car was compliant under NEDC but non-compliant under WLTP when it was exported into a new country. 


Existing Models

This isn’t a country-specific regulation, but it’s important to know just the same. In certain cases, existing car models that were already on the market and certified under NEDC before the mandatory implementation of WLTP were allowed to remain in circulation without undergoing re-testing. 

The biggest example of this are late-year 2017 models that were in production as WLTP came into power. This can result in NEDC values still being accepted for a limited number of existing models.


Specific Implementation Dates 

The precise dates for the mandatory use of WLTP has varied among EU member states. 

Some countries might have had a gradual approach to the implementation of WLTP for new registrations. For example, in Belgium, NEDC values were accepted until January 2021. In the Netherlands, this date was 1 July 2020.

If you’re a used car dealer operating across the EU, these exemptions and specific cases are important to take note of. Otherwise, you might be selling cars that were compliant in one country and none compliant when they crossed the border to a country with different regulations.

All in all, there are some sensitive cases in which you will have to do additional research to ensure the car your selling is compliant in the country where your customer resides. 

In the following section, we’ll provide you with resources for verifying CO2 values.

What You Can Do To Ensure CO2 Compliance of Your Used Vehicles

With the help of all this information, you are now perfectly set to ensure the cars you’re selling are CO2 compliant, wherever you’re operating from. All that’s left to do is for us to give you some resources for verifying CO2 values.

As mentioned, cars that were compliant at the time of production will come with a Certificate of Conformity (COC) where this is mentioned. This information may also be available in the owner’s manual of the car. 

Some online databases will also have CO2 values and emission compliance information readily available. There are two kinds of these databases. 

The first ones can be accessed through the car manufacturers’s website. In most cases, you can just look up the car’s specifications and read the CO2 values. Here’s Volvo’s specs for the XC60, for example:

Car manufacturer websites usually carry CO2 values on specification pages

How to find out the correct CO2 value?

Fortunately, for some countries, there are national resources that will let you check the car’s CO2 values according to its chassis number and/or current license plate. In the next few sections, we’ll explain how to use those resources for cars registered in Belgium and the Netherlands to give you an easy way to instantly know the CO2 values of cars in those countries. We’ll also explain how to find the information when such resources aren’t available.



For Belgian cars, use the resource on this link. Once you land on the page, simply type in the VIN number in the field below and click the green button:

Check the CO2 values for Belgian cars


The results you get will provide various details about the vehicle, and among them the CO2 values. In our example below, we looked up a car registered in 2018 and got CO2 values for both NEDC and WLTP.


The Netherlands

To check the correct CO2 value for Dutch cars, you can check the RDW website. In this case, you will be entering the plate number into the search bar.

Check the CO2 values for Dutch cars


The Dutch database will give you an even richer source of information about the vehicle and you’ll have to navigate to the section dedicated to the environmental impact of your vehicle. There, you’ll find CO2 values for the testing procedures that was used.


On eCarsTrade, we display NEDC and WLTP values for most of Belgian and Dutch cars. Here’s where you can find that data on our platform. 

However, to make extra sure the information is correct, we still recommend that you verify those numbers with the help of the two resources for Belgian and Dutch cars.


► Our Other Origin Countries - France, Germany, and Luxembourg

As for German and Luxembourg cars, the CO2 values should be mentioned on the COC or the registration documents. 

French cars do not come with a COC, so if you’re buying a French car from 2018, contact us and we’ll do our best to figure out the CO2 values together.

If the car has already arrived at our location in Belgium, we can check the registration documents for you in order to figure out the CO2 value for certain. Relying on online sources always leaves a small chance that the values might not be correct.

Before we wrap up this section, let’s recap the best and most effective ways to check your CO2 values, according to where the car your’re sourcing was first registered.

Finally, remember that you can always contact your account manager for help and/or clearing out any doubts.

Stay CO2 Compliant With eCarsTrade

So, as you can see, although CO2 emission compliance can be quite complex to understand and achieve, there are always resources you can use to check CO2 values and make more informed purchases. 

Apart from car manufacturers and national databases, eCarsTrade is at your disposal as you’re sourcing cars for your buyers.

The European Union consists of countries that may have different regulations on a variety of automotive matters. That’s especially true for CO2 emission standards where the transition from NEDC to WLTP has resulted in some dilemmas for automotive professionals.

To ensure your stock is compliant with regulations, check out our offer of thousands of used cars with dependable information on CO2 values.