Just like choosing the right motor oil, mixing oils from different brands is a frequently discussed topic. So what’s the truth?
🔍 1) Mixing doesn’t instantly damage the engine — but it’s not ideal.
Due to API and ACEA requirements, most oils on the market meet basic compatibility standards. In an emergency, adding another brand with the same viscosity grade usually won’t cause immediate harm.
⚙️ 2) The issue lies in differing additive packages.
Each manufacturer formulates detergents, dispersants, anti-wear agents, and friction modifiers differently.
When these packages mix:
- Performance may degrade
- Oxidation may accelerate
- Deposit control may weaken
In short: “It works, but not optimally.”
📚 3) Matching API/ACEA specs isn’t enough.
Just because two oils are API SP doesn’t mean they’ll perform the same when mixed.
Even OEM-approved product lists (Mercedes, BMW, VW, Ford, etc.) clearly state that mixing oils is not recommended.
🧪 4) Synthetic–mineral mixing is technically possible, but not advised.
Modern synthetics can chemically blend with mineral oils.
However, this can reduce:
- Thermal stability
- Cold flow performance
- Long-term protection
🧭 5) Best practice: Use the same brand and series.
Full performance is only achieved when the oil works with its own additive system. Mixing is an emergency fix, not a routine method.
🎯 Bottom Line
Mixing oils isn’t “dangerous” — it’s “inefficient.”
For engine health, always choose one brand, one series, and the correct specification.
#LubricantCompatibility #OilMixingMyths #EngineCareTips #LubeFacts
