Can motor oils of the same brand be mixed?
2 Answers
Motor oils of the same brand cannot be mixed. Although they share the same brand, different specifications of motor oils adhere to varying standards, viscosities, and low-temperature tolerances in winter, making them incompatible for mixing. Methods for selecting motor oil include: 1. The oil should appear clear with a sulfur content of less than 1%; 2. The weight of residual carbon content should be less than 1%; 3. The volume of water and sediment should be less than 0.1%; 4. The weight of ash content should be less than 0.03%. The functions of motor oil include: 1. Lubrication; 2. Assisting in cooling and temperature reduction; 3. Cleaning carbon deposits and sludge from engine components; 4. Sealing to prevent gas leakage and the entry of external contaminants; 5. Rust and corrosion prevention; 6. Shock absorption and cushioning; 7. Anti-wear properties.
As someone who works with cars year-round, I have to say mixing engine oils is really unreliable. Using the same brand might sound safe, but oils have viscosity differences, like 5W-30 and 10W-40. Mixing them reduces lubricity, making engine components prone to wear. The formulations also differ—synthetic and mineral oils can have conflicting additives, causing chemical imbalances and shortening oil effectiveness. Adding a small amount in an emergency is acceptable, but don’t rely on it; switch to a uniform oil ASAP. Using the same oil type during regular maintenance is key to avoiding engine overheating or failures, saving big on repairs. Remember, the engine is a precision machine—mixing oils is like playing a risky game.
