Can engine oils be mixed for use?

[VanAyla]

Engine oils should not be mixed. Additional information: 1. Consequences of mixing: If it is necessary to mix engine oils, be aware that mixing different types of oils may result in turbidity. Since different brands and types of engine oils contain different chemical additives, mixing these chemicals may lead to chemical reactions, reducing lubrication effectiveness and potentially forming acidic or alkaline compounds that accelerate corrosion of engine components. 2. It is advisable to use multi-grade oils: Multi-grade oils have excellent viscosity-temperature performance, last longer in engines, save fuel, and are suitable for all seasons, making them easier to manage. When using multi-grade oils, the oil color tends to darken, and the oil pressure may be lower than that of conventional oils. These are normal phenomena and do not affect usage.

[SanJesse]

Let me share my personal experience with mixing engine oils – after driving several cars, I've learned it's truly unreliable. Different brands of engine oil vary significantly in chemical composition, and their additives can easily conflict. Mixing them reduces lubrication effectiveness, increases engine friction, and in mild cases leads to higher fuel consumption and reduced power, while severe cases can cause component wear requiring major repairs. Last year, when my car was low on oil, I casually topped it up with another brand as an emergency measure. A few days later, the engine started making constant abnormal noises. After inspection, it turned out that sediment had clogged the filtration system. For regular maintenance, I insist on using the manufacturer-specified grade of oil and change it every 5,000 kilometers to protect the engine. Mixing oils might seem like a quick fix for shortages, but it carries long-term risks, increases repair costs, and shortens the vehicle's lifespan. Before an oil change, ensure all the old oil is completely drained before refilling with the same new oil to keep the engine running smoothly and durably. In case of urgent need, mixing small amounts once or twice is acceptable, but a complete oil change should be done as soon as possible to avoid cumulative damage.

[VanMaddox]

As someone who loves researching cars, I've tested mixing engine oils a few times and don't recommend it. The core issue lies in viscosity and additive incompatibility - mixing may cause separation or chemical reactions, losing rust prevention and anti-wear functions while accelerating engine aging. Different base oil materials (like synthetic mixing with mineral oil) can thicken or thin, affecting flow protection. Chemical incompatibility also leads to sludge buildup clogging oil passages and reduced cooling efficiency. In emergencies when mixing different brands, I observed noticeable engine temperature rise and noise. Always follow manual-specified viscosity and brands for regular 5,000km changes to prevent premature overhaul. When changing oil, fully drain before adding new oil to ensure purity. Small mixed amounts are temporarily feasible during oil shortage, but shouldn't exceed one trip - address it promptly.

[StJeremiah]

Mixing different engine oils is highly hazardous, a point I've emphasized for years. Mixing oils causes additive conflicts and viscosity imbalance, reducing lubrication and leading to increased engine wear, component damage, or even cylinder explosion. A single repair can cost thousands and may total your vehicle. Always use the same specification oil and perform regular checks to prevent risks.