BNOx System für Blaue Plakette
BNOx System

BNOx At a glance

  • Effectiveness proven in ADAC EcoTest
  • Meets “Real Drive Emissions” requirements (Euro 6c)
  • NOx reduction rates of 95% possible
  • “Real Drive” NOx emissions are reduced by 94%
  • Reduction of particulate emissions by more than 99%
  • Highly efficient SCR system, optimised for cold engine running conditions
  • The system functions already from an exhaust gas temperature as low as 150°C (vs. 220°C)
  • Takes up less space due to compact design
  • No deposition of AdBlue in the exhaust system
  • Certified according to Millbrook (UK); TÜV (DE) and EPA (USA) under verification

BNOx Presentation

Current News about the BNOx System

20.02.18 NTV: Bundesverwaltungsgericht entscheidet über Diesel-Fahrverbote
13.02.18 3Sat: Ferdinand Dudenhöffer: "An der Hardwareumrüstung kommt niemand vorbei"
13.02.18 Spiegel: Benziner sind die neuen Diesel
05.02.18 ZDFwiso: Den alten Diesel richtig nachrüsten, welche Möglichkeiten gibt es?
29.01.18 NTV: In diesen Städten sind Diesel-Fahrverbote wahrscheinlich
28.01.18 Focus: Autoexperte warnt: "Zehn deutschen Städten drohen Fahrverbote für Dieselfahrzeuge"
18.01.18 Welt: Fahrverbote kann Deutschland kaum noch verhindern
10.01.18 Reuters: Union und SPD wollen Diesel-Nachrüstungen durchsetzen

Show more News...

Diesel vehicles prohibited
Stuttgart takes the first step

On 21 February 2017, Stuttgart became the first German city to prohibit, with effect from 2018, access by diesel vehicles that do not meet the emission limits of the EURO 6 standard – and in so doing, Stuttgart also got the ball rolling for many other large German cities. In order to meet the EURO 6 standard, diesel vehicles must lower their NOx emissions to below 0.08 g/km. Vehicles that do not meet at least the EURO 6 standard are at risk of losing considerable value.

What is the blue sticker

As with the existing green sticker for EURO 4 vehicles, only vehicles that satisfy the EURO 6 standard will obtain the blue sticker. Older vehicles with the blue sticker will still be able to enter designated blue zones in cities and municipalities if they are upgraded to the EURO 6 values with a retrofit solution such as the BNOx system. The introduction of blue stickers and their requirements are currently under discussion at the federal level in Germany. If the blue sticker is introduced, it would offer owners of older model vehicles a way to minimise their loss in value and to maintain their mobility while preserving the environment at the same time.

BNOx System
The problem

If legislators do not adopt and introduce the blue sticker, several million diesel vehicles are at risk of being prohibited from entering large cities with heavy nitrogen oxide pollution levels. This would cause such vehicles to lose a tremendous amount of value.

EURO Normen und Grenzwerte Diagram 1: EURO standards and exhaust values measured under real conditions in 2014
The Solution
The Baumot BNOx System

With the BNOx system, the Baumot Group offers a retrofit solution that lowers nitrogen oxides by more than 90% under real conditions (RDE1). The emission values it achieves under real conditions in retrofitted vehicles of pollution class EURO 4 and higher are better than those of the current EURO 6 category. In future, this would enable you to qualify your vehicle for the blue sticker and gain access to "blue zones".

Standard SCR System
BNOx System
BNOx Nachrüstkit
BNOx System
Grafik 2: Reduktion von Stickoxiden unter realen Bedingungen (= niedrige Abgastemperaturen) um über 90%

The diagram on the left shows that with a standard SCR system, effective NOx conversion occurs only at exhaust temperatures above about 220°C. Such temperatures are achieved only rarely, if ever, under real conditions in on-road operation, however. From the diagram on the right, it is clear that the BNOx system can already achieve a significantly greater NOx reduction at lower exhaust temperatures. Among other benefits, this makes it possible to significantly reduce nitrogen oxide emissions by up to 94% during on-road operation, even at low exhaust temperatures (starting from approx. 150°C).

The high nitrogen oxide reduction rate at low temperatures is especially important to automakers, because in future, testing must also be carried out under real road conditions (RDE1) with a PEMS2 measurement device (EURO 6c). In those tests, the prevailing exhaust gas temperatures are significantly lower than with the previous test stand methods.

This means that the BNOx system already meets future legal requirements for on-road measurements (EURO 6c) today. With the BNOx system, passenger cars of pollution class EURO 4 or higher can comply with at least EURO 6 emissions limits.

This has been proven in multiple independent trials.

In collaboration with global OEM customers, the system was developed for series production and expanded under strict quality standards into a dependable, compact exhaust purification system for original equipment and retrofit applications.

1 RDE, Real Driving Emissions
2 PEMS, Portable Emissions Measurement System

Would you like to know more about the technical details, such as the design configuration or the operating principle of our BNOx system? Then download our information brochures here:


The answers to frequently asked questions about the BNOx system can be found here.

to the F.A.Q.
Case Study 1
DUH6 Tests on a retrofitted VW Passat B7 1,6 TDI (EU5)

This diagram shows the nitrogen oxide (NOx) emissions of a passenger car tested according to pollution class EURO 5 standards under laboratory conditions. Two different test cycles were used: the current EURO 6 test method (WLTC1, test stand) and the EURO 6c RDE2 cycle, which will apply from September 2017. (PEMS3, on-road).

Along with the BNOx system, the upgrade included the installation of existing VW EURO 6 series production components from the original VW spare parts catalogue4Bars 1 and 4 indicate the NOx exhaust gas values (0.68 g/km and 0.079 g/km) under the new EURO 6 test method, WLTC1. Bar 1 shows that according to the WLTC1 method, the EURO 5 vehicle emits over seven times more nitrogen oxides  (0.68 g/km) and is therefore far above the EURO 5 limit of 0.18 g/km under real conditions. Bar 4 shows the same test where the vehicle was retrofitted with the BNOx system. The NOx emissions are reduced to  0.079 g/km and achieve, by comparison, an NOx reduction of 88,4 % under real conditions in the WLTC1 test. Bars 2 and 5 show a PEMS3 measurement without  (1.03 g/km) and with BNOx  (0.069 g/km) according to EURO 6c approval procedures in Berlin. An NOx reduction of 93.3 % is achieved there with the BNOx retrofit kit.

For comparison purposes, bar 3 shows the NOx emissions (0.118 g/km) of a comparable EURO 6 vehicle5. Versus the EURO 5 vehicle with BNOx system (0.069 g/km), it emits nearly twice the quantity of NOx.

From this, it is clear that the retrofitted EURO 5 vehicle complies with the EURO 6 limit values, also under real conditions.

As the results show, the BNOx retrofit kit makes it possible to retrofit EURO 5 passenger cars and comply with EURO 6 limit values even under real conditions.

BNOx System Diagram 3: Real NOx emissions in comparison (DUH)
limit NOx [g/km]
Test cycle NOx emissions [g/km] NOx emissions
w/o BNOx [g/km]
NOx reduction
with BNOx
1 EURO 5 0,18 WLTC1 0,68 - -
2 EURO 5 0,18 PEMS3 1,03 - -
3 EURO 6 0,08 PEMS3 0,228 - -
4 EURO 5 0,18 WLTC1
with BNOx
0,079 0,68 -88,4 %
5 EURO 5 0,18 PEMS3
with BNOx
0,069 1,03 -93,3 %
table 1: Detailed NOx emissions
Feasibility Study

Passenger cars Commercial vehicles Busses
Number of EU 5 / EU IV vehicles
(25% of the stock in germany)
aprox. 1'370'000 aprox. 25'000 aprox. 5'000
Cost retrofit system aprox. 2'000 €/ System aprox. 12'000 €/ System aprox. 12'000 €/ System
Total cost - Retrofit 2'740 Mio € 300 Mio € 60 Mio €
External cost - environmental damage caused by NOx 15'400 €/t 15'400 €/t 15'400 €/t
NOx emissions (current) aprox. 28'000 t/year (total) aprox. 5'400 t/year (total) aprox. 3'000 t/year (total)
NOx Reduction by BNOx 90% 90% 90%
NOx emissions after BNOx retrofit aprox. 2'800 t/year (total) aprox. 540 t/year (total) aprox. 300 t/year (total)
Total damage caused by NOx aprox. 431 Mio €/year aprox. 83 Mio €/year aprox. 46 Mio €/year
Cost savings by BNOx retrofit aprox. 388 Mio €/year aprox. 75 Mio €/year aprox. 41 Mio €/year
Amortisation after
2'740 Mio € / 388 Mio € = 7,06
8 years
300 Mio € / 75 Mio € = 4
4 years
60 Mio € / 41 Mio € = 1,46
2 years

Source: Data refers to numbers from the report "Umfassende Bewertung zu marktverfügbaren fahrzeugseitigen NOX-Nachrüsttechnologien" of the federal environmental agency
NOx: Common abbreviation for nitrogen oxides (NO or NO2)

Frequently asked Questions

More Questions?

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T: +49 (0) 2244 9180-40


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