Mar 24, 2023
Posted by Keith Howard, Strategic Technology Manager, Mark Dewey, Strategic Technology Manager
This article highlights the key takeaways from our recent webinar, Euro 7 - The Next Chapter in European Vehicle Emissions Regulations. You can view the full webinar and register for upcoming webinars here.
In late 2022, the European Commission announced the Euro 7 vehicle emission regulations. The initiative will enact stricter standards for all gasoline and diesel vehicles across the light- and heavy-duty spectrum. Euro 7 will go into effect July 1, 2025, for new light-duty vehicles and July 1, 2027, for new heavy-duty vehicles—and the entire automotive value chain must prepare itself for the implications.
Euro 7 is a significant change from the current Euro 6. With the ultimate goal of improving urban air quality, Euro 7 will push towards ultra-low emissions levels for all new vehicles, under all operating conditions, for the full useful life of the vehicle.
OEMs will need to implement significant changes to engines and aftertreatment devices to meet the standards. And to best enable these technology changes, high-quality fuels and lubricants will be a necessity. Let’s explore some of Euro 7’s requirements and the ramifications they will have on the European automotive market:Light-Duty Requirements
Widened Real Driving Emissions (RDE) Testing. Euro 7 standards build upon RDE testing of Euro 6, broadening the driving and environmental conditions under which emissions tests are valid, helping to account for the differing climates, topographies and road conditions throughout the continent. Euro 7 limits will also be tested across trips shorter than 10 kilometers. This measure is intended to prevent a vehicle from being relatively dirty at startup, which is then mitigated by the vehicle operating more cleanly later in the cycle. This is a challenge, as vehicles produce much higher levels of emissions when cold.
Conformity Factors Eliminated. Where past Euro standards applied conformity factors to account for lower accuracy of portable emissions measurement systems (PEMS), Euro 7 eliminates conformity factors entirely. The increased accuracy of the latest PEMS systems is a key factor in this decision, which in effect means that RDE limits are tightened even further.
Extended Emissions Durability. Euro 7 will expect new passenger cars to maintain very low levels of emissions performance for 200,000 kilometers or 10 years—double the expectations of Euro 6. Additionally, monitoring throughout this time period will become far more granular, as the standard will require onboard sensors and systems that can provide a detailed history of emissions performance and pinpoint specific emissions system problems.
In response to these changes, we anticipate OEMs to pursue a range of strategies to meet the new limits and testing protocols. For gasoline powered vehicles, we expect GDI technology to remain as the key engine technology. Gasoline particulate filters (GPFs) will also become universal, and they will need to become more efficient in order to provide outstanding performance down to PN10 from the outset.
For diesel powered vehicles, NOx control will be especially critical at startup. In order for NOx reduction systems to become effective as soon as possible after startup, OEMs may close-couple the devices near the engine itself, rendering them more vulnerable to contamination. They may also choose to electrically heat the NOx reduction catalyst. Elsewhere, particulate control during DPF regeneration may be especially challenging. Regeneration, where the exhaust temperature is increased to burn built-up soot off the DPF, inherently leads to a spike in emissions that may be at odds with Euro 7 limits, and could impact filter design moving forward.
For both fuel types, expect to see furthering of hybridization to drive down CO2 emissions and improve fuel economy.
Lower Limits for all Pollutants. All limits for heavy-duty emissions will become stricter and will include a few new additions. Heavy-duty standards will add formaldehyde and nitrous oxide and, as with light-duty standards, will set limits on particulate emissions as small as PN10.
Emphasis on RDE testing. Where Euro 6 test limits for heavy-duty vehicles were based on pre-defined test cycles, Euro 7 will place a much greater emphasis on RDE testing. It will further modify its limits to account specifically for cold-start emissions, which are especially important for urban driving, as well as emissions over the full RDE test.
Extended Emissions Durability. As with light duty, Euro 7 seeks to extend emissions limits throughout the useful life of the vehicle. For N2 and N3 commercial vehicles less than 16 tons, and for M3 commercial vehicles less than 7.5 tons, Euro 7 limits will apply for 375,000 kilometers or eight years (up from 300,000 kilometers or six years in Euro 6). For N3 vehicles greater than 16 tons, and for M3 vehicles more than 7.5 tons, limits will apply for 875,000 kilometers or 15 years (up from 700,000 kilometers or seven years).
Heavy-duty engine technology and aftertreatment systems will need to change in order to meet these new requirements. NOx control at the levels required by Euro 7 will be challenging, particularly during cold start, and will likely drive dramatic changes to the selective catalytic reduction (SCR) systems used to reduce NOx emissions. As with light-duty diesel drivetrains, close- coupling and electric heating will likely be explored here. DPF regeneration will also pose challenges.
Implications for Lubricants and Fluids
The new Euro 7 requirements and the engine and aftertreatment device changes that they will spur have significant implications for both the lubricants and fuels throughout the European vehicle parc.
A few of these include:
PN10 Concerns. Euro 7’s new PN10 limits are inherently incompatible with lower-quality engine oils. The Worldwide Harmonized Light Vehicles Test Cycles (WLTC), as shown in the accompanying graph, demonstrates that engines filled with high-ash, high-volatility engine oils generate elevated levels of particulates between the PN10 and PN23 range. This will necessitate the use of high quality lubricants in new model vehicles throughout their useful life to meet Euro 7’s standards for PN10 particulates and extended emissions durability.
Particulate Filter and Catalyst Compatibility. High-ash content in a lubricant can also cause problems with a vehicle’s aftertreatment device. Over time lubricant will cause filter blockage, which can lead to an increase in back pressure in the exhaust system. When such back pressure occurs, the engine must work harder to expel exhaust, leading to higher fuel consumption. Other lubricant components can also cause issues here. Sulphur and phosphorus content can poison the catalytic coatings of aftertreatment devices, which in particulate filters leads to poor soot burn-off, also creating increased back pressure and higher fuel consumption.
Fuel Injector Deposits. Within any modern engine, fuel injectors are finely calibrated to deliver precise quantities of fuel at exactly the right timing to create optimal, efficient combustion. Lower-quality fuels, however, tend to generate deposits that can interfere with an injector’s performance. Over time, deposit buildup on fuel injector nozzles can interfere with fuel delivery to the combustion chamber, leading to longer and less efficient Injection events. Such events can result in both higher emission levels and lower levels of fuel efficiency. Both conditions are at odds with Euro 7 standards, and as such, high-quality fuels will be necessary for new engines to meet the requirements throughout their useful lives.
LSPI Mitigation. Euro 7 will usher more GDI engines into the vehicle population, which are susceptible to a phenomenon called low speed pre-ignition (LSPI). LSPI is an irregular combustion event that can lead to catastrophic engine damage. But modern, high-quality lubricants can help mitigate the risk of LSPI and should be seen as a prerequisite.
Hybridization Enablement. Euro 7 will likewise spur the introduction of more hybrids into the population. In hybrid drivetrains, an internal combustion engine (ICE) complements an electric motor. The duty cycle for the ICE in this application, however, is fundamentally different than in a traditional ICE-powered vehicle. The ICE may only operate for short periods of time to provide a charge for the electric motor’s battery, or to provide more power when required. Short operation intervals mean the engine does not reach high temperatures for extended periods and may not fully burn off condensation within the engine. As a result, such condensation can lead to corrosion of engine parts. Engine oils with high levels of corrosion protection are therefore required in hybrid applications.