Oil bottles have many symbols. Here is the simple explanation.
1. SAE Viscosity Grade
Example: 5W-30
Meaning:
- 5W = Good for cold start
- 30 = Stability at high temperature
Smaller number = thinner oil
Bigger number = thicker oil
2. API Rating
API is the American Petroleum Institute.
Gasoline engines:
- SP (latest, best)
- SN
- SM
Diesel engines:
- CK-4
- CJ-4
Always choose SP or SN for gasoline cars.
3. ACEA Rating
Used mainly in Europe:
- A/B = Gasoline + diesel passenger cars
- C = Low SAPS for modern engines
- E = Trucks
Example:
- C3 = Best for modern European engines
- A5/B5 = Fuel economy oils
4. OEM Approvals
Some oils have manufacturer approval:
- Toyota Approved
- BMW LL-01
- Mercedes 229.5
- Volkswagen 504/507
If your car is European, choose oil with OEM approval.
Conclusion
When reading a bottle, check:
- SAE grade (0W-20, 5W-30, etc.)
- API rating (SP is best)
- OEM approval (if required)
Now you can buy oil confidently.