Currently reading: New Bosch diesel tech to ‘fix’ NOx problem
German engineering firm pushes emissions far below required levels using existing hardware

Bosch has revealed details of new technology that it claims can drastically reduce nitrogen oxide levels in diesel cars, essentially fixing the problem that has caused their recent downturn.

Diesel sales have tumbled in recent months as regulators aim to lower output of NOx, which is associated with respiratory problems in humans in urban environments.

Bosch claims that it has developed a solution that not only reduces NOx output in diesel engines but practically eliminates it so it falls to a point that’s almost a tenth of the next-generation limits.

“We call our system active thermal management because it keeps the most important part of the diesel exhaust, the exhaust gas recirculation (EGR) system, running at its optimal temperature,” Bosch diesel division development boss Michael Krüger told Autocar.

EGRs work best when they are heated by waste gases to more than 200deg C, but Krüger said this temperature is rarely reached when cars are driven at low revs through urban environments.

'Diesel saving' technology could make it to market in two years

“If you were to coast or not touch the accelerator, the EGR would cool far below its optimum temperature, so NOx levels are higher,” he said. "With our system, the point is to minimise all temperature losses by packaging the EGR as close to the engine as possible.”

By pushing the EGR closer to the engine, the part can be kept closer to 200deg C Celsius for longer, thanks to the heat soak surrounding the engine bay. Bosch’s new system also intelligently manages the movements of gases to ensure only hot gases travel through the EGR.

These processes, which are said to use existing hardware already equipped on modern diesel vehicles, are claimed to trim NOx output to as low as 13mg/km in real-world driving scenarios. This not only far undercuts the current limit of 168mg/km, it also easily beats the next-generation limit of 120mg/km, which comes into force in 2020.

Krüger said this development could prove pivotal in ensuring that car manufacturers meet future CO2 targets. Diesel’s downturn has seen petrol sales increase, in turn driving up average CO2 outputs. He said that diesel therefore remains extremely important as electrification begins to grow.

“We are really taking care of finding the best overall compromise,” he said.

While Bosch doesn’t comment on its customers, it is well known that the firm supplies a large number of the world’s biggest manufacturers, including the Volkswagen Group and Mercedes-Benz – emphasising the impact this new system could have.

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Chris C 26 April 2018


This sounds like car manufacturers properly engineering the plumbing/location of their EGR systems - hardly groundbreaking rocket science but it may mean larger packaging space under the bonnet and better heat dissipation therefrom.

What about particulate emissions from tyres and brake pads?

What about increased emissions by the extra input required to produce petrol distillates from what would otherwise be heavy oil/diesel in oil refineries? 

Peter Cavellini 26 April 2018


 Can it be fitted to the Methane Kings....Cows!? Any rumanunt?, hmm, to get back to the article now, yeah this seems like nirvana for the Car industry  but it still has to be tested by  the powers that decide it’s ok, if it’s fine then the sooner the better!!!

xxxx 26 April 2018


for Diesel engines to work all you need to do a 2.0 petrol NA engine:

Add a Turbo, make the casings stronger and heavier, add a complicated expensive PDF, ADBlue injection system, add an a EGR - simples.  All add to cost, complexity, weight, service costs then start to fail after 6 years and smoke like a kipper