We know that many clients have been waiting a long time for progress in their claim and will want to understand what this recent judgment means for them. We also know that some of the issues involved in diesel emissions litigation can be complex and difficult to follow.

This update aims to explain as clearly as possible what the court decided, what it did not decide, what it means for your claim, and what may happen next. It is not legal advice about your individual claim.

In summary
The most important thing to know is that your claim remains ongoing. The recent judgment is not the end of the Mercedes litigation.

The result was mixed. The judge agreed with the claimants on some important issues and agreed with Mercedes on others. Neither side got everything it wanted from this stage of the case.

In particular:
• The judge found that Mercedes used a cycle recognition defeat device, known as the CTS device.
• The judge accepted that vehicle owners may, in principle, have a legal claim where the emissions regulations have been breached.
• The judge did not accept all of the allegations made against Mercedes.
• No compensation has been awarded at this stage.
• Further stages of the litigation are still to come.
• The claimant legal teams are reviewing the judgment carefully, including whether there are grounds for an appeal.

There is nothing you need to do at this stage.

What does this mean for my claim?
Your claim is still active.

The judgment does not bring the Mercedes claims to an end and it does not decide whether clients will receive compensation. A number of important issues still need to be decided before the litigation reaches a final outcome.
Importantly, the judge recognised that vehicle owners may have a valid legal claim where the emissions regulations have been breached. This is an important finding because it confirms that claimants are entitled, in principle, to pursue claims through the courts rather than the regulations being enforceable only by regulators.

Although the judge rejected the argument that the presence of a prohibited defeat device automatically establishes a breach of contract, she did not bring the claims to an end. Significant aspects of the claimants’ case remain live, and a number of important issues — including compensation — will be considered at later stages of the litigation.
This judgment is an important step forward in the litigation, but it is not the final outcome.

What stage of the litigation are we at?
This hearing was about deciding key legal and technical issues, including whether certain systems used in diesel vehicles were unlawful and how the relevant emissions regulations should be interpreted.

This was not the final trial.

It was what lawyers call a liability trial. In simple terms, the court was considering questions about legal responsibility.

The judge was not deciding:
• how much compensation claimants should receive;
• whether individual claimants should be paid damages;
• the value of individual claims; or
• many of the issues that would still need to be decided before compensation could be awarded.

This will come in separate, later stages.

What was the judge asked to decide?
The judge was asked to consider the European emissions regulations and decide whether particular systems used in certain sample vehicles were prohibited defeat devices according to those regulations.

The court was asked to decide a number of issues, including:
• what legally amounts to a prohibited defeat device;
• what “normal driving conditions” means;
• when a reduction in emissions-control performance becomes unlawful;
• whether the systems identified by the claimants were unlawful;
• how the regulations should be interpreted; and
• whether manufacturers could rely on exceptions contained within the regulations.

These issues involved extensive technical evidence from engineers, software specialists and emissions experts, as well as legal submissions from both sides.

How did the judge approach the case?
One of the main disagreements in the litigation was about how the emissions regulations should be interpreted. The claimants argued that previous European court decisions showed that many emissions control strategies used by manufacturers were unlawful.

The judge adopted a narrower interpretation than the claimants had argued for. She concluded that a prohibited defeat device, on her primary interpretation, must be able to recognise that it’s in a testing environment and result in the emissions control system operating more effectively during testing than during normal driving.

This was an important part of the judgment because it shaped how the judge assessed many of the allegations made against vehicle manufacturers.

The judge also concluded that:
• manufacturers were not required to meet emissions limits in every conceivable real-world driving condition;
• previous European decisions should not automatically be followed without careful analysis; and
• the regulations must take account of engineering realities such as reliability, durability and engine protection.#

Importantly, the judge recognised that the outcome could be different if a higher court takes another view of how the regulations should be interpreted. This is one reason why the judgment is now being reviewed carefully by the claimant legal teams.

What did the judge decide about Mercedes vehicles?
Mercedes was one of the four lead manufacturers selected for the liability trial. The court considered four Mercedes sample vehicles and a number of emissions-control systems used in Mercedes diesel vehicles.

One of the most significant findings concerned the CTS device. The judge found that the CTS was a cycle recognition defeat device.

What is the CTS device and why is it important?
The CTS (Cycle Test Sensing) device was one of the key Mercedes systems examined during the liability trial.
The judge found that the CTS system could identify when a vehicle was undergoing the official emissions test and would respond differently during that testing process.

This was an important finding because emissions tests are intended to show how a vehicle performs in normal use, not just in a laboratory environment. The court’s finding on the CTS device therefore represents one of the most significant Mercedes-specific findings in the claimants’ favour.

However, like many parts of this judgment, the position is not entirely straightforward. The judge also concluded that the claimants had not established that the CTS resulted in the necessary reduction in effectiveness. In other words, while the court accepted an important aspect of the claimants’ case, it did not accept every allegation made about the impact of the CTS device.

The judge also did not accept a number of the allegations made about other Mercedes systems, including thermal window strategies, atmospheric pressure corrections, engine temperature calibrations, engine start and idle strategies and SCR dosing strategies. This was largely because she adopted a narrower interpretation of the regulations than that argued for by the claimants.

Overall, neither side got everything it wanted from the Mercedes part of the judgment. However, the Mercedes claims remain alive and important issues are still to be decided.

How did the other manufacturers fare?
The judgment also considered Ford, Peugeot/Citroën, Renault and Nissan vehicles. The results were mixed across those manufacturers as well, with some allegations succeeding and others not.

This is relevant because the litigation is being managed as part of the wider Pan-NOx proceedings and some of the legal findings will help guide the future direction of diesel emissions claims more generally.

Is KP Law considering an appeal?
Our legal team is now reviewing the judgment carefully and considering all available options. This includes whether there are grounds to seek permission to appeal parts of the decision.

To pursue an appeal there must be proper legal grounds to do so. An appeal cannot be pursued simply because a party disagrees with the result.

The issues being examined for appeal include:
• the interpretation of the emissions regulations;
• the judge’s approach to European authorities after Brexit;
• the meaning of “normal driving conditions”; and
• the evidence required to prove a reduction in emissions-control effectiveness.

It is still too early to confirm whether an appeal will be pursued, but this remains under active consideration and we will let clients know if there are any important developments.

How long could an appeal take?
If an appeal does take place, the litigation is likely to take longer to reach a final outcome.

We understand that many clients have already waited a long time for progress and may find any further delay frustrating.

Unfortunately, this is a common feature of large group litigation involving complex evidence, important legal issues and substantial potential liabilities. Cases like these often pass through several stages and, in some circumstances, multiple appeals before reaching a final conclusion.

Importantly, additional time does not mean that the claims have failed.

Likely next steps
The next stages may include:

• Detailed review of the judgment.
• Consideration of potential grounds for appeal.
• An application for permission to appeal, if appropriate.
• Further case management by the court.
• Future stages dealing with unresolved liability and compensation issues.
• Further client updates when there is a material development.

What do clients need to do now?
At the moment, there is nothing you need to do.

We will continue to review the judgment, consider the next steps and keep clients informed of any significant developments.

Please ensure that your contact details remain up to date so that we can contact you if there are important updates about the litigation, any appeal process, settlement developments or requests for further information.