Diesel cars may have just been saved by an innovative new tech

Diesel cars have been condemned since the revelation that they create a lot of noxious emissions. 

British drivers were encouraged to buy diesel cars in 2001 as they were thought to be more efficient and they, typically, emit less CO2 emissions. 

Noxious emissions, however, can cause heart disease, strokes and even lung cancer. 

Many countries including the UK is introducing measures to ban these vehicles and impose restrictions or taxes to reduce the use of these cars. 

However, Continental could have found a solution to this issue. 

The component supplier has developed a 2.0-litre VW Golf Mk7 GTD which emits 60 per cent less NOx than a standard car. 

In addition to this, the vehicle’s fuel consumption improved by four per cent and the CO2 emissions were also reduced. 

“The diesel engine will continue to play an important role in meeting mobility needs for the foreseeable future,” says José Avila, President of the Powertrain Division and Member of the Executive Board of Continental. 

“So it is vital for us to develop the technology to support extremely low-pollutant diesel operation.”

Engineers at Continental implemented the clean diesel system in a  number of stages. 

Firstly they replaced the standard injection system with Continual’’s PCRs5 piezo common rail injection system, which operators with maximum injection pressures of 2,500bar

With the help of highly dynamic valve timing it is possible to perform multiple, very closely spaced and very precisely metered injections per cycle.

This allows a minute amount of fuel to be injected after the combustion event. 

The fuel only ignites when it reaches the catalyst, which therefore accelerates the process of heating it up.. 

Catalysts or catalytic converters are what is used on diesel cars to convert nitrogen oxide emissions

These systems, however, only operate at certain temperatures and are typically functional on motorways or highways but are less effective in stop/star urban driving environment.

Tests show that this single measure – post-injection – can cut the SCR catalyst light-off time by around eight minutes, resulting in a reduction in cumulative nitrogen oxide emissions under the future WLTP (Worldwide harmonized Light-duty Test Procedure) driving cycle of 37 percent.

Due to this, however, there would be an increase in fuel consumption which is why a 48 Volt Hybrid System was introduce. 

The 15kW system allows regenerative braking but can also assist in the internal combustion engine in short, sharp bursts of acceleration. 

This is said to reduce peaks in nitrogen oxide emissions that are a feature of diesel engines under sudden, heavy throttle acceleration. 

The 48 Volt system can in total reduce NOx emissions by a further three per cent.

A further reduction is achieved by the uses of a close-couple electrical heated catalyst (EMICAT) which brings the other downstream-minted catalyst up to operating temperature within 30-40 seconds. 

This allows it so start converting NOx but also keep the catalyst at operating temperate in all driving scenarios, where it would usually cool down in slow traffic. 

Additionally the connected Energy Management (cEM) and Traffic Light Assist can also be used to slash emissions. 

The beauty of ‘connected Energy Management’ is that we can implement a more energy-efficient driving strategy simply by using an improved database,” says Dr. Oliver Maiwald, Head of Technology & Innovation with Continental’s Powertrain Division.

“When the cEM control unit is aware of the upcoming route (thanks to the navigation system or learning algorithms), it can decide in advance when the vehicle should coast and when it is best for it to recuperate braking energy, thereby saving fuel and emissions,” says Maiwald.

The TLA predicts when the next traffic light will be on red and can use this information to improve coasting, recuperation and braking management. 

The advancement in diesel engines made by Continental was revealed earlier this year at the 2017 Vienna Motor Symposium. 

 “In other words we have resolved a classic conflict of objectives in diesel engine development,” says José Avila, “showing that a clean diesel engine with emissions well within the legal limits doesn’t have to consume more fuel.”