Mazda says it's ready for the near future. All new models, with the exception of the Mazda 3, which is due to receive a successor by next year, will be certified according to the strictest Euro 6d TEMP emission standard. It includes the new WLTP (Worldwide harmonized Light vehicles Test Procedure) emission measurement methodology as well as the RDE (Real Driving Emissions) road test for controlling harmful emissions.
Mazda will thus meet the strict criteria more than a year before the new emission standard becomes mandatory for all cars. The first Mazdas with the aforementioned emission standard will roll off the production line in July of this year. But Mazda came up with something original after all…
In short, the Japanese car manufacturer is a sucker for technical innovation, and therefore it is not surprising that it achieved clean emissions even without a costly and complex intervention in the treatment of exhaust gases. For example, Skyactiv-G gasoline engines with direct injection, more precisely the 1.5, 2.0 and 2.5 liter capacity, meet the conditions of the Euro 6d TEMP emission standard even without the use of particulate filters. The automaker managed to meet the set RDE limits only thanks to modifications to the engines.
As for the 2.2 Skyactiv-D diesel engine, it is newly equipped with the SCR (Selective Catalytic Reduction) system. In other words, the engine now includes AdBlue urea, thanks to which NOX (nitrogen oxides) standards have been met in operation. As for the new 1.8 Skyactiv-D unit, it is not equipped with AdBlue, thanks to a specific catalyst for NOX.
Petrol engines must have a new DPF, Mazda says no!
Skyactiv-G gasoline engines are equipped with a very high compression ratio and a special combustion system, which serves as the basis for efficient and clean combustion. Instead of installing particulate filters, Mazda significantly reduced emissions by increasing the injection pressure and by modifying the shape of the pistons and the flow conditions in the combustion chamber. Furthermore, reducing friction losses and optimizing the cooling system also helped. And the result is really worth it – Skyactiv-G engines are more efficient than ever and at the same time produce very few harmful emissions.
Skyactiv-D 2.2 cannot do without SCR
Skyactiv-D engines with an extremely low compression ratio belong to the most efficient aggregates, especially in real operation. They first arrived on the market in 2012 and already met the Euro 6 emission standard at launch, which only came into force about two years later. The unit has undergone major changes to meet the requirements of the Euro 6d TEMP standard, so it now has a modified combustion chamber shape, variable blade geometry for the larger of the two turbochargers, new thermal management and multi-phase combustion with new piezo injectors. These not only reduce emissions, but also have better response and lower noise. However, the main innovation is the SCR system, as I mentioned at the beginning.
Skyactiv-D 1.8 does not need AdBlue, thanks to a special catalyst
In the 1.5 Skyactiv-D successor, more precisely in the 1.8 Skyactiv-D unit, the larger engine volume is transferred to a lower maximum combustion pressure and combustion chamber temperature, which is further reduced by a combination of high and low pressure exhaust gas recirculation. The lower combustion temperature with a number of other improvements means that the engine produces less nitrogen oxides and thus the presence of the catalyst is fully sufficient to meet the Euro 6d TEMP standard. The advantage over SCR is the absence of AdBue, which saves owners time and money.
WLTP and RDE – main weapons Euro 6d TEMP
At the end, I will try to describe the mentioned new methodologies so that the reader can get an overview. So the emissions and fuel consumption values are newly determined according to the WLTP, which replaces the NEDC (New European Driving Cycle). WLTP is supposed to offer a more realistic view of emissions in real traffic, as it takes into account parameters such as vehicle weight, ambient temperatures, tire pressure and rolling resistance. The WLTP test cycle is also longer than NEDC with a higher average and maximum driving speed. Like NEDC, WLTP is carried out on a cylinder test bench, allowing direct comparisons between vehicles. The Euro 6d TEMP standard also includes, among other things, RDE, which takes into account harmful emissions in road transport for a change.
The Euro 6d TEMP standard came into effect on 1 September 2017 for the approval of new vehicle types and will be applied to all new registrations from 1 September 2019.