Euro 5 diesel engine cars showing Ulez compliant on tfl website
Request ID: FOI-3195-2223 Date published: 20 March 2023
You asked
Dear Transport for London,
On a number of used car sales websites I have come across atleast over a 200 cars with Euro 5 diesel engine (from 2010 to 2016) that I have personally checked on Ulez checker on TFL site thst are showing compliant.
Can you please answer following questions:
1. I understand there are a number of criteria that TFL says it uses to assess a cars compliance to Ulez, can you please provide a detailed list of criteria as it has not been made available anywhere on TFL site?
2. How accurate is Ulez checker site's database?
3. Given that data on cars older than 3 years is available to TFL in entirety, is it right to assume that Ulez non-compliant data on TFL is "frozen" and there will be no updates or changes to it anytime in future and hence the cars showing compliant or non-compliant today will maintain the same status?
4. What makes any Euro 5 diesel engine car compliant to Ulez?
5. What makes any Euro 5 diesel engine car Non-compliant to Ulez when compared to a Ulez compliant Euro 5 car?
We answered
TfL Ref: FOI-3195-2223
Thank you for your request received by Transport for London (TfL) on 27th February 2023 asking for information about the Ultra Low Emission Zone (ULEZ).
Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy.
I can confirm that we hold the information you require. Your questions are answered in turn below:
Question 1. I understand there are a number of criteria that TFL says it uses to assess a cars compliance to Ulez, can you please provide a detailed list of criteria as it has not been made available anywhere on TFL site?
And;
Question 2. How accurate is Ulez checker site's database?
Petrol cars must be Euro 4 or have NOx emissions equal to, or less than, 0.08 grams per kilometre. Diesel cars must be Euro 6 or have NOx emissions equal to, or less than, 0.08 grams per kilometre and Particulate Matter emissions equal to, or less than, 0.005 grams per kilometre
In order to establish whether a vehicle is compliant with the ULEZ emission standards we predominantly use the vehicle data held by the DVLA. In most cases we can establish a vehicle’s compliance status by the date it was first registered as new. We know that all diesel cars first registered as new after 1 September 2015, and all petrol cars first registered as new after 1 January 2006 are automatically compliant with the ULEZ standards. This is because there was a legal requirement on manufacturers to produce vehicles to Euro 4 (petrol) and Euro 6 (diesel) standards as of those dates.
Using the data provided by the DVLA we have developed a compliance database which lists the compliance status of all UK registered vehicles. This is not a live link to the DVLA data rather a static list of vehicles which is refreshed with new updated DVLA data every month. By updating the list regularly it ensures any update to vehicle information held by the DVLA is reflected on our database.
We acknowledge that the information held by the DVLA may not always allow us to establish whether a vehicle is compliant, not least because there is no requirement for them to record a vehicle’s emissions. We therefore supplement the DVLA data with information from the Vehicle Certification Agency and information sourced from vehicle manufacturers.
We have also set up an enquiry service which allows motorists to contact us if they believe that the compliance details we hold are incorrect. This allows them to provide information to us on their vehicle and request that we update the compliance status. If we receive information which confirms compliance we will update our records and mark the vehicle compliant. Such evidence could include a Certificate of Conformity from the vehicle manufacturer which specifically details the NOx and PM emissions of the specific vehicle.
Question 3. Given that data on cars older than 3 years is available to TFL in entirety, is it right to assume that Ulez non-compliant data on TFL is "frozen" and there will be no updates or changes to it anytime in future and hence the cars showing compliant or non-compliant today will maintain the same status?
Answer: We base a vehicle’s compliance status on what we know about a vehicle at any given time. As outlined above the enquiry service allows a motorist to provide information to us regarding a specific vehicle. If we are presented with additional information relating to a vehicle, which changes the compliance status, then our records would be updated. Therefore the compliance status can be amended.
Question 4. What makes any Euro 5 diesel engine car compliant to Ulez?
And;
Question 5. What makes any Euro 5 diesel engine car Non-compliant to Ulez when compared to a Ulez compliant Euro 5 car?
Answer: To be compliant a diesel car must have NOx emissions equal to, or less than, 0.08 grams per kilometre and Particulate Matter emissions equal to, or less than, 0.005 grams per kilometre. A diesel car will only be compliant if it meets these standards.
Therefore, if a vehicle was listed as being Euro 5 diesel but we are provided with evidence that the aforementioned emissions are met, then the vehicle would be marked as compliant.
If this is not the information you are looking for please do not hesitate to contact me.
Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.
Yours sincerely,
David Wells FOI Case Officer FOI Case Management Team General Counsel Transport for London
