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German OEMs to upgrade emissions control on 5.3M Euro 5 and 6 diesels, contribute to €500M Sustainable Mobility fund

German auto manufacturers will optimize the emissions systems in 5.3 million currently approved Euro 5 and 6 diesels in the country, according to the outcome of the “National Diesel Forum” held in Berlin today between the automotive industry and the German Federal and state governments. The aim is a 30% reduction in NOx emissions from these vehicles by the end of 2018. The automakers will bear the entire cost of the retrofitting, estimated by the German Association of the Automotive Industry (VDA) to be at least €500 million.

Among other actions detailed in the declaration of the Forum, the automakers will fund a €500-million “Sustainable mobility for the city” fund. The aim is to develop and implement an individual master plan (“green-city plan”) for each of the 28 regions designated by the EU Commission particularly affected by high NO2 pollution, with digitization, intelligent transport systems, intermodal mobility solutions and with increasing automation and networking in individual and public passenger transport.

With respect to the emissions updates, the OEMs must also provide proof that the changes do not negatively impact any other parameters relevant for type approval—such as pollutant and CO2 emissions, fuel consumption, noise and engine power.

A consumer advisory board will be set up for the consumers in the Federal Office of Motor Vehicles.

The Federal and state governments also expect the manufacturers to use self-financed competitive measures to provide incentives for the change of pre-Euro-5 diesel vehicles to vehicles with the latest exhaust gas aftertreatment or electric vehicles.

For Euro-6 vehicles, the manufacturers must also state explicitly that the technically optimal function of the SCR catalytic converter is ensured in all newly registered vehicles in all driving situations on the road. This applies in particular to the use of urea for exhaust gas purification in achieving the highest efficiency achieved in this process.

At Wednesday’s National Diesel Forum. Left to right: Rupert Stadler (Audi), Dr. Herbert Diess (Volkswagen), Matthias Müller (Volkswagen), Dr. Dieter Zetsche (Daimler), Harald Krüger (BMW), Matthias Wissman (President of VDA). Click to enlarge.

In attendance from the government side were Alexander Dobrindt, Federal Minister of Transport and Digital Infrastructure; Dr. Barbara Hendricks, Federal Minister for the Environment, Nature Conservation, Building and Nuclear Safety; Dr. Wolfgang Schäuble, Federal Minister of the Interior; Brigitte Zypries, Federal Minister for Economic Affairs and Energy; Prof. Dr. Johanna Wanka, Federal Minister of Education and Research; as well as the Prime Ministers of Baden-Wuerttemberg, Bavaria, Hesse, Lower Saxony, North Rhine-Westphalia, Rhineland-Palatinate, of the Saarland and the Governing Mayor of Berlin and the First Mayor of Hamburg .

Excessively high pollution affects air quality in many German cities. Nitrogen oxide emissions (NOx) in particular require comprehensive efforts to improve the health protection of citizens. Although NOx emissions were reduced by just under 60% between 1990 and 2015, the NOx load in 28 German cities and agglomerations is still higher—in some cases significantly higher—than the EU-imposed limit values.

…The most urgent task therefore is the reduction of NOx pollution from diesel vehicles as well as the further optimization of diesel technology—for the health protection of citizens, in the interest of the quality of life and functionality of our cities and for the mobility needs of citizens and the economy.

…In today’s talks, the federal government and the federal states have made it clear that they have a rapid, comprehensive and robustly effective immediate program to reduce the NOx load on diesel engines in service as well as significant technological efforts to improve diesel technology. This also includes the further optimization of the diesel drive. A strong contribution is needed to support the acutely affected municipalities to avoid flat-rate driving bans for diesel vehicles within the scope of their air pollution plans.

…In addition, a broad understanding and a clear strategy of the future are to be developed in order to actively shape the mobility of the future and the transformation process of the entire automobile industry towards emission-free and digitally networked mobility. The industry is now required to bring a convincing range of alternative drives and mobility solutions to market maturity on this basis.

… On the way to emission-free vehicles, the possibilities for optimization and efficiency potential still present in combustion technology must not be ignored. In this sense, modern and clean diesel technology can also contribute to climate protection. Combustion engines will be necessary in the foreseeable future for individual mobility and freight transport. Motor vehicle owners are also entitled to the protection of their trust. We will also examine the contribution of synthetic fuels to the reduction of pollutants and greenhouse gases. We pursue a technology-oriented approach.

—Declaration of the National Diesel Forum

Other measure outlined in the declaration include:

  • Strengthening state control. The German KBA will also test exhaust emissions even with approved vehicles. For this purpose, the KBA will regularly remove vehicles from the market and check them for compliance. The KBA will also carry out its sampling controls on vehicles for which other authorities have granted the type approval. These measures have already been launched in connection with the publication of the report on the Volkswagen investigation commission of the BMVI. Road measurements will also be carried out to check the NOx reduction. The Federal Government will report on the results.

  • Further steps required. The technical upgrades are only a first step towards reducing the NOx emissions of diesel engines in cities. Automakers must develop and present technically feasible and economically justifiable concepts for further upgrading of emissions controls—for example, through the installation of additional exhaust gas purification systems. The automotive industry is also required to apply the European regulations concerning the introduction of RDE much earlier. To this end, the German manufacturers will submit a concept by October 2017.

  • Promotion programs for improved air quality and sustainable mobility. Targeted support programs provide important impulses for the reduction of pollutant emissions. The Federal Government will therefore expand and expand the support platforms for pollution-reducing measures in urban transport.

  • E buses. A main focus will be on electric buses. The subsidy for the purchase of electric buses in public transport will be raised to 80% and the total subsidy volume increased to €100 million euros per year. The promotion of hybrid buses as well as natural gas buses (CNG) will be continued and intensified.

  • Purchase subsidies for low-emission municipal commercial vehicles. Also for this segment, more electrified solutions are to be developed and implemented.

  • Municipal acquisition of E-vehicles. The subsidy of 40% of the additional investment costs for municipal taxis and vehicles will be increased. In addition, the municipalities will be given the opportunity, by means of changes in the right to transport passengers, to impose higher emission requirements on inner-city operation than in the past.

  • Rail transport. The Federal Government will expand the existing subsidy of hybrid trains and / or trains with hydrogen and fuel cell technology , which are significantly lower in comparison to pure diesel engines.

  • Land power supply in sea and inland ports. The reduction of pollutant emissions from ships during lunches is an important contribution to air pollution in port cities.



Beating up the car companies is good fun, as they have been cheating but you have to look at the whole problem and remove the worst vehicles from the cities completely, if they cannot be "fixed". By this I mean buses, bin trucks and other delivery vans - anything that is polluting, including diesel trains.

They will probably need a combination of "worst offender removal" and bringing Euro 5 and 6 cars up to spec.

I wonder how they can suddenly do this - it is simply a case of using more Urea in the "Add blu" systems or is there more to it than that. If they do use more Urea, surely the cars will need to have the tanks refilled more frequently, or have larger containers fitted.

I await enlightenment.



DEF (urea solution) usage will likely increase in these circumstances. It's also probably at least one reason why manufacturers cut corners in the first place - to allow a tank of DEF to last through a full service interval without placing a huge DEF tank in the vehicle.

BMW is using a combination of a LNT (called a "passive NOx adsorber" - "PNA") and SCR for their diesel cars in the U.S. The PNA adsorbs NOx during engine start-up or periods where the SCR isn't sufficiently warm to convert the NOx to N2. The NOx is desorbed from the PNA when the SCR is sufficiently warm.

The U.S. BMW diesel cars/SUVs have been shown to have extremely low NOx emissions.


The irony here is that heavy-duty vehicles actually are extremely clean compared to light-duty vehicles. A big truck can have lower emissions per kilometer than a small car and if we look at weight-specific emissions, the difference can be monumental. Here, I specifically refer to “actual” on-road (RDE) emission levels of NOx. It may sound strange, since similar SCR technology is used in both cases. I do not have time to elaborate on this at the moment but I can perhaps explain this in a later post. We also know that some Euro 6 light-duty (diesel) vehicles are also clean. Perhaps not fully down to the level of the best gasoline cars but still far below the on-road limit in RDE testing. As pointed out by Carl, a lot of DEF (Adblue in Europe) must be used, particularly so for some heavy-duty vehicles. For reducing NOx, we have three major technologies: EGR (here I would like to include both high-pressure and low-pressure EGR but internal EGR could also be considered), NOx-storage catalyst (NSC or LNT, which you prefer) and SCR. Surprisingly, many “clean” heavy-duty vehicles do not use ANY kind of EGR and LNT is not used in any case to my knowledge. The technology that has enabled this trend is significant improvements in SCR-technology for heavy-duty vehicles during the last couple of years. We are talking about NOx conversion rate of up to 99%. By combining with EGR and LNT, a reduction of NOx by a factor of 10 compared to current Euro VI is not impossible to envision for heavy-duty vehicles. The actual implementation depends on emission regulation (potential Euro VII). It is more difficult to get similar improvements on light-duty vehicles but it will gradually come. Recall that very few cars still have both high-pressure and low-pressure EGR. Some have LNT, some have SCR but very few have both. Carl mentioned BMW but there are a few additional examples. There are also several technologies in the pipeline for increasing SCR efficiency significantly; perhaps not to the level on heavy-duty vehicles but much better than we have today. By reducing engine-out NOx and “after LNT” NOx, the “burden” on the SCR system will actually decrease. Thus, the practical solution of a relatively small Adblue tank and refill only during maintenance can still be obtained.

Regarding technology, I do not have any doubt about that very low NOx emissions can be obtained. In addition, it will not cost a fortune. Perhaps the incremental cost will still be too high for the smallest cars but it will not be a show-stopper for medium and larger cars. Recall that some cars already have this technology. Regarding other emissions compounds of health hazard, diesel car are already much better than gasoline cars but this is a discussion we can leave for the moment. The actual “problem” we face today is that some manufacturers have not respected the intention of the regulation, i.e. to give low emissions under all operating conditions. To be honest to the car manufacturers (if one can be than under the circumstances?...), some operating conditions have not been regulated by the legislators, so they could be considered as grey zones. This is the target for the coming RDE regulation. Ironically, Euro 6 cars from the VW group are quite good when it comes to NOx; at least, in comparison to many other car manufacturers. We know they cheated in Euro 5, and in the USA, but this does not concern cars sold today. Finally, we should not underestimate public opinion. This alone can – and will – for sure have a tremendous impact on sales. If people do not want diesel cars, interest from car manufacturers will diminish and development will be stopped.


There is another way to reduce NOx and it can be retrofitted to any diesel: Propane fumigation. The reason Diesels produce so much NOx is that they run oxygen rich at high temps. Adding propane takes some of the O2 out of the equation. Running a diesel on a 50/50 mix of diesel/propane can reduce NOx by 50% and because propane is a low carbon fuel it can also reduce CO2 by 10%. Additionally, it reduces soot.


Propane fumigation would have even bigger problems with NOx than diesel engines. This is why we do not see such engines on the road anymore. You simply have to meet the emission limits to sell a vehicle. Propane is best used under stoichiometric conditions where you can use aftertreatment three-way catalyst (TWC). Engine-out emissions are higher than for diesel also in this case but TWC is more efficient aftertreatment than SCR, so we end up with lower tailpipe NOx. Propane and gasoline are roughly equal in this respect. Recall that a gasoline engine also has higher engine-out emissions than a diesel engine. The drawback of stoichiometric combustion is lower efficiency.


All I know is what I read;

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