Exhaust emissions from off-highway combustion engines are estimated by the European Commission to contribute approximately 15 percent of nitrogen oxides (NOx) and 5 percent of particulate matter (PM) to air pollution in Europe. In addition, the European Commission has found NOx and PM to have “adverse ill effects” on public health, making continued improvements to air quality essential.
For off-highway diesel engines, Stage I, II, III and IV emissions standards have been introduced gradually from 1999 onwards, each tightening various emissions limits. Stage IV was introduced in 2004 with updates rolled out up to 2012. In 2016, the European Commission proposed Stage V as the world’s most stringent emissions standard for off-highway diesel engines, even surpassing the US Tier 4 Final standards. Stage V introduces particulate number (PN) limits for the first time and mandates carbon monoxide (CO), hydrocarbon (HC), PM and NOx limits across a much broader range of engine kW power ratings. PM limits are also now 40% lower versus Stage IV for engines rated between 56-560 kW.
What Does Stage V Cover?
When compared to Stage IV, Stage V covers a larger range of engines, including:
- Compression Ignition (CI) engines below 19 kW and above 560 kW
- Spark Ignition (SI) engines above 19 kW
- Other previously unregulated engines
The Stage V standard applies to many markets including mobile off-highway machinery, hand-held machinery, inland waterway vessels, railway locomotives, railcars, snowmobiles, all-terrain vehicles, side-by-side vehicles and generating sets. The most substantial impact is on diesel engine models within construction and agriculture, with all off-highway vehicles facing compliance irrespective of engine size.
Stage V is applicable to all countries within the European Union and will most likely also followed by other countries within Europe, such as Norway and Switzerland.
When Was Stage V Implemented?
The Stage V standard was implemented in January 2019. From then onwards, no additional Stage IV engines could be produced. Original Equipment Manufacturers (OEMs) were given a two-year window to utilize existing Stage IV engine inventory and place them into the market. This means that, by January 2021, all new off-highway equipment will be fitted with engines certified to the Stage V standard. However, as a result of the COVID-19 pandemic this timeline has recently been modified for off-highway equipment <56kW and ≥130kW. The timeline has been extended by 12 months for both building machines installed with non-Stage V, transition engines (now June 30, 2021) and placing them into the market (now December 31, 2021).
Impact on Lubricant Requirements
The introduction of Stage V poses new aftertreatment system challenges for OEMs, with most requiring their equipment to feature a combination of Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR). In comparison to Stage IV, compliance with the Stage V emissions standard will be nearly impossible to achieve without the use of a DPF.
For an off-highway engine lubricant, these stringent requirements necessitate the correct engine lubricant formulation and performance additive technology selection to ensure efficient aftertreatment system and engine performance. The widespread adoption of advanced aftertreatment devices will significantly increase market demand for lubricants with lower levels of Sulphated Ash, Phosphorus and Sulphur (SAPS). These lubricants will need to align with ACEA E6 or ACEA E9 and API CK-4 industry performance baselines alongside associated OEM approvals.
The Stage V emissions standard has driven the development and implementation of new hardware and emissions systems strategies. In turn, these strategies have introduced new durability and compatibility concerns for OEMs and end users. To resolve many of these concerns, high performance lower SAPS engine lubricants will be required which adhere to the relevant lower SAPS ACEA and API industry performance levels and applicable OEM approvals.
For more information on lower SAPS engine lubricants, please contact your Lubrizol representative.