Exhaust Mobile sources - Pollutant exhaust gases created by the combustion of fuel. Water and CO2 are not included in this category, but CO, NOx, and hydrocarbons are and are thus subject to legislative control. All three are emitted by gasoline engines, while diesel engines also emit particulates that are regulated. Stationary sources - The release of sulfur oxides and particulates from power stations that can be influenced by fuel composition. Local authorities control the sulfur content of heavy fuel oils used in such applications. 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.
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 A reaction occurring when oxygen attacks petroleum fluids. Oxidation is accelerated by heat, light, metal catalysts, and the presence of water, acids, or solid contaminants. Oxidation leads to increased viscosity and deposit formation. 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 A product of the combustion of metals commonly found in detergents. As a lubricant property, sulfated ash content is a measure of metal content (usually Zinc, Calcium, and Magnesium) and allows formulators to stay within specified limits in order to minimize the negative effects of abrasive ash particles. Sulfated ash is determined by charring the oil, treating the residue with sulfuric acid, and evaporating to dryness, the result being expressed as % by mass., Phosphorus and Sulphur (SAPS). These lubricants will need to align with European Automobile Manufacturers Association (Association des Constructeurs Européens d'Automobiles). The primary automotive standards organization in the European Union, ACEA defines performance specifications for automotive lubricants. E6 or ACEA E9 and American Petroleum Institute. The primary oil and natural gas trade association in the United States. API operates a voluntary licensing and certification program that allows engine oil marketers to use the API Engine Oil Quality Marks if their products meet specific requirements. 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.