Historical China VI Emission Standards and Their Requirements for Engines and Oils

发布时间：2022年01月08日 15:14

What is China’s Stage VI Emission Standard? “China Stage VI” is the common nickname for the country’s sixth-phase motor vehicle emission standards. The Stage VI standard represents an upgrade over the previous Stage V standard. Compared to Stage V, Stage VI imposes significantly stricter limits on pollutant emissions. Specifically, for gasoline vehicles, the Stage VI standard reduces carbon monoxide emissions by 50%, cuts total hydrocarbon and non-methane hydrocarbon emission limits by 50%, and tightens nitrogen oxide emission limits by 42%. The Stage VI standard is divided into two phases: Phase 6A and Phase 6B. Phase 6A began on July 1, 2020, prohibiting the sale, registration, and licensing of vehicles that fail to meet the Stage 6A emission standards. Phase 6B, starting from July 1, 2023, will similarly ban the sale, registration, and licensing of vehicles that do not meet the Stage 6B emission standards. Currently, some regions have already begun implementing these standards ahead of schedule. How do the emission limits of Stage V and Stage VI differ? Compared to the Stage V standard, Stage VI—especially Stage VI B—significantly improves emission performance. Here’s a comparison of emission limits between Stage V and Stage VI: | Emission Type | Stage V | Stage VI A | Stage VI B | Reduction (%) | |---------------|----------|------------|------------|--------------| | CO (Carbon Monoxide) | 1000 | 700 | 500 | 50% | | THC (Total Hydrocarbons) | 100 | 100 | 50 | 50% | | NMHC (Non-Methane Hydrocarbons) | 68 | 68 | 35 | 48% | | NOx (Nitrogen Oxides) | 60 | 60 | 35 | 42% | | PM (Particulate Matter) | 4.5 | 4.5 | 3 | 33% | To meet the stringent Stage VI emission standards, newly launched vehicles—whether heavy-duty trucks or passenger cars—must adopt new technologies and components in their engines, such as turbocharged direct-injection technology (TGDI), exhaust gas recirculation (EGR), selective catalytic reduction systems (SCR), and particulate filters (DPF or GPF). These technologies are now widely used in engines. The new technologies and components introduced in Stage VI engines place special demands on engine oils: Turbocharged direct-injection technology can easily lead to early combustion at low speeds, requiring lubricants that can effectively inhibit sludge and carbon deposits around the combustion chamber and fuel injectors. Additionally, selective catalytic reduction systems and particulate filters contain precious metals like platinum, gallium, and palladium, which are prone to oxidation and damage; therefore, both fuel gasoline and lubricating oils must have low sulfur and low ash content. To ensure smooth operation and extend the lifespan of Stage VI engines, existing oil grades no longer meet the requirements, necessitating the development of higher-quality Stage VI-specific oils. As a result, the new SP-grade oil standard has been introduced. What is API? API stands for the American Petroleum Institute. The API rating indicates the quality grade of an oil, but it’s important to note that this quality grade does not directly reflect anti-wear performance alone—it represents a “comprehensive quality threshold,” including environmental performance. API ratings are categorized into two main groups: oils for gasoline engines, labeled with “S,” and oils for diesel engines, labeled with “C.” There are also universal lubricants that carry both “S” and “C” designations, compatible with both gasoline and diesel engines within a certain range. Gasoline-engine oils with “S” ratings include: SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN, and the newer SP rating. Why update the standards? In response to increasingly stringent national environmental regulations and energy-saving requirements, automakers are adopting various technologies—including engine downsizing, direct injection, turbocharging, reduced friction, and advanced exhaust treatment and combustion technologies—to further improve fuel efficiency and meet emission standards. For passenger cars, the trend in traditional powertrains has shifted gradually from larger displacement engines to smaller ones: 2.0-liter engines are being replaced by 1.6L, 1.5L, and 1.3L engines, and naturally aspirated engines are giving way to turbocharged engines. These changes all require higher-quality lubricants to provide adequate hardware protection and prevent operational issues, while also leveraging lower viscosity grades to enhance fuel economy. As a result, the lubricant industry faces ever-greater challenges, and updating lubricant formulations has become imperative. From the earlier API SA to today’s API SN, SNplus, and the recently announced API SP, each new standard brings higher requirements for various lubricant parameters. Currently, the mainstream grades in the engine oil market are API SN and SNplus. As the industry continues to evolve, oils of SL grade and below will gradually be replaced by other products. Meanwhile, the SP-grade oil, designed to meet the Stage VI engine requirements and align with national environmental policies, is poised to become the market’s dominant choice in the future.

What is China VI?

“National Stage VI” is the common nickname for the country’s sixth-phase motor vehicle pollutant emission standards.

The China VI emission standards represent an upgrade over the China V standards. Compared to the China V standards, the China VI standards impose stricter limits on pollutant emissions. Specifically, for gasoline vehicles, the carbon monoxide emissions are reduced by 50%, the total hydrocarbon and non-methane hydrocarbon emission limits are lowered by 50%, and the nitrogen oxide emission limits are tightened by 42%.

The “China VI” standards will be divided into two phases: Phase 6A and Phase 6B. The first phase, effective July 1, 2020, prohibits the sale, registration, and licensing of vehicles that fail to meet the Phase 6A emission standards. The second phase, effective July 1, 2023, will prohibit the sale, registration, and licensing of vehicles that fail to meet the Phase 6B emission standards. Currently, some regions have already begun implementing these standards ahead of schedule.

Differences in Emission Limit Requirements Between China V and China VI

Compared to the China V standards, China VI—especially China VI B—represents a significant improvement in emission standards.

Differences in Emission Limit Requirements Between China V and China VI
Emissions	National Level 5	China VI A	China VI B	Reduce
CO—Carbon Monoxide	1000	700	500	50%
THC hydrocarbons	100	100	50	50%
NMHC: Non-Methane Hydrocarbons	68	68	35	48%
NOX Nitrogen Oxides	60	60	35	42%
PM particles	4.5	4.5	3	33%

To meet the stringent China VI emission standards, newly launched vehicles—whether heavy-duty trucks or passenger cars—must equip their engines with new technologies and components, such as turbocharged gasoline direct injection (TGDI), exhaust gas recirculation (EGR), selective catalytic reduction systems (SCR), and particulate filters (DPF or GPF), which are now widely adopted in engines.

The new technologies and components introduced in the China VI emission standard engines place special demands on engine oils: Turbocharged direct-injection technology can easily lead to early ignition at low speeds, requiring lubricants that can effectively inhibit the buildup of sludge and carbon deposits around the combustion chamber and fuel injectors. Moreover, selective catalytic reduction systems and particulate filters contain precious rare metals such as platinum, gallium, and palladium, which are prone to oxidation and degradation. Therefore, both gasoline and lubricants must exhibit low-sulfur and low-ash characteristics.

To ensure the smooth operation and extended lifespan of China VI engines, the current oil grades no longer meet the requirements and need to be replaced with higher-quality China VI-compatible oils. As a result, the new SP-grade oil standard has been introduced.

What is API SP?

API stands for the American Petroleum Institute. The API rating indicates a quality grade; however, it’s important to note that this quality grade does not directly reflect wear resistance alone—it represents a “comprehensive quality threshold” that includes environmental performance as well. API ratings are categorized into two main groups: oils for gasoline engines, which begin with the letter “S,” and oils for diesel engines, which begin with the letter “C.” There are also universal lubricants that bear both “S” and “C” designations, making them compatible with both gasoline and diesel engines within a certain range. The API ratings for gasoline-engine oils beginning with “S” include: SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN, and the newer SP.

Why should we update the standard?

To meet the increasingly stringent environmental regulations and energy-saving requirements issued by the government and to comply with China’s Stage VI emission standards, automakers are adopting a variety of technologies—including engine downsizing, direct injection, turbocharging, reduced friction, and advanced exhaust aftertreatment and combustion technologies—to further enhance vehicle fuel efficiency and ensure compliance with emission standards. For passenger vehicles, the trend in conventional powertrains has been shifting gradually from larger-displacement engines to smaller ones: 2.0-liter engines have progressively given way to 1.6L, 1.5L, and 1.3L engines, while naturally aspirated engines are being replaced by turbocharged ones.

And these changes all require higher-quality lubricants to provide adequate hardware protection, prevent vehicle operational issues, and, at the same time, enhance fuel economy by using lower viscosity grades.

Therefore, the lubricant industry is facing increasingly higher challenges, and it has become imperative to update lubricant formulations. From the earlier APISA to today’s APISN, SNplus, and the more recently announced APISP, each new standard at every stage has raised higher requirements for various performance indicators of lubricants.

Currently, the mainstream grades in the engine lubricant market are API SN, SN Plus. As the industry continues to evolve, oils of SL grade and lower will gradually be replaced by other products. Meanwhile, SP-grade National VI oils, in line with market trends and national environmental protection policies and regulations, meet the requirements of National VI engines and are bound to become the market’s mainstream in the future.

The “production + service” model is becoming the direction for lubricant companies.

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