The impact of engine anti-wear repair agents on exhaust emissions requires comprehensive analysis considering their composition, usage scenario, and engine operating conditions. These products reduce friction and fill wear gaps by forming a protective film on metal surfaces, theoretically reducing combustion chamber clearance, improving sealing, and thus optimizing combustion efficiency and reducing emissions of unburned hydrocarbons (HC) and carbon monoxide (CO). However, actual effectiveness is limited by product formulation, usage method, and engine condition, and in some cases may lead to worsened exhaust emissions or even malfunctions in the exhaust aftertreatment system.
The core mechanism of a high-quality engine anti-wear repair agent is the formation of a high-strength protective layer. These products typically use nano-sized single-molecule hydrocarbons or metal particles as carriers, penetrating the metal surface through thermal activation technology to fill micro-scratches and form a mesh film. For example, repair agents containing molybdenum alloy components can generate a hexagonal crystalline film under high temperature and pressure, significantly reducing the coefficient of friction and minimizing internal engine friction losses. This type of protective layer not only improves power output but also enhances cylinder sealing, allowing for more complete fuel-air mixing, theoretically helping to reduce the content of harmful substances in exhaust gases.
However, the quality of remedial agents on the market varies greatly, and some inferior products may even contribute to exhaust pollution. These products often contain excessive amounts of phosphorus, zinc, and sulfur, and the ash generated after combustion can easily clog the gas particulate filter (GPF) and the three-way catalytic converter. The GPF is a key component in the exhaust treatment of diesel vehicles and some gasoline vehicles; its blockage leads to increased exhaust back pressure, reduced engine power, and the direct emission of unfiltered particulate matter, exacerbating air pollution. The three-way catalytic converter is responsible for converting CO, HC, and nitrogen oxides (NOx) into harmless gases. If it is covered by ash, its catalytic efficiency will decrease significantly, and the concentration of pollutants in the exhaust will increase significantly.
The compatibility of remedial agents with engine oil is also an important factor affecting exhaust emissions. Modern engine oils are precisely formulated balances containing various additives such as anti-wear, cleaning, and dispersing agents. Adding additional remedial agents may disrupt this balance, leading to abnormal oil viscosity or changes in pH. For example, excessive addition may cause oil viscosity to spike, increasing engine operating resistance and forcing the ECU to adjust fuel injection, leading to increased fuel consumption and incomplete combustion, which in turn results in excessive HC and CO levels in the exhaust. Furthermore, the chemicals in the repair agent may react with oil components to form corrosive gum, exacerbating internal engine wear and creating a vicious cycle.
During cold starts, the mechanism of action of the repair agent may have a dual effect. During a cold start, the oil has not yet fully reached the lubrication points, causing concentrated engine wear. High-quality repair agents can quickly form a protective film, reducing wear during this period and preventing untreated fluid from entering the crankcase, thus lowering exhaust emissions. However, inferior products may have slow film formation or poor adhesion, failing to effectively protect metal surfaces and instead increasing the content of volatile organic compounds (VOCs) in the exhaust due to component evaporation or incomplete combustion.
The potential risks of long-term use of repair agents should not be ignored. Even if the product itself is of acceptable quality, failure to change the oil regularly as required by the instructions or the use of multiple additives may result in an excessively thick metal protective film, affecting piston ring elasticity and even causing oil burning. When an engine burns oil, the oil enters the combustion chamber and participates in combustion, generating a large amount of blue smoke. The heavy metal particles and unburned oil components contained in this smoke significantly worsen exhaust quality and damage the three-way catalytic converter.
From an environmental and engine health perspective, the use of engine anti-wear repair agents requires careful product selection and strict adherence to regulations. Prioritize purchasing reputable brands that meet national standards and clearly label their ingredients and applicable scope, avoiding the use of unknown or substandard products. Before adding the agent, confirm the oil type and replacement cycle. New cars or well-maintained engines typically do not require additional additives. If the engine has experienced severe wear or oil burning issues, repair agents can only provide temporary relief; thorough repair remains the fundamental solution. Regular maintenance, using high-quality engine oil, and proper driving habits are the most reliable ways to reduce emissions and extend engine life.
