01
SAE 5W-30
5W concerns cold cranking (CCS) and pumpability (MRV). Grade 30 involves high-temperature viscosity, including kinematic viscosity at 100 °C and HTHS requirements. SAE J300 defines these limits.
AMERICOPP TECH · ENGINE OIL · TIP 1/20
5W-30 ≠ 5W-30
Two lubricants can display exactly the same SAE grade while meeting different performance requirements and manufacturer specifications.
Americopp rule
Viscosity is part of the specification. It is not the entire specification.
Choosing oil only because the bottle says 5W-30, 0W-20 or 0W-30 does not establish that it is suitable for a particular application.
Technical sequence
02
Same viscosity, different performance
API category, ACEA classification, HTHS, additives, fuel economy, emissions-system compatibility and OEM approvals can differ between two SAE 5W-30 products.
03
API, ILSAC and ACEA
The series illustrates API SP/SQ, ILSAC GF-6/GF-7 and ACEA A3/B4, C2, C3, C5, C6 and C7. Depending on the category, requirements address wear, deposits, sludge, LSPI, timing-chain wear, oxidation, fuel economy and emissions-system protection.
04
Manufacturer requirements
Examples include BMW LL-01/LL-04/LL-12 FE/LL-17 FE+/LL-22 FE++, VW 502 00/504 00/505 01/507 00, MB-Approval 229.x, GM dexos and Ford WSS. Select the requirement for the actual engine, rather than from this example list.
05
Workshop comparison
Oil A in the illustration declares SAE 5W-30, API SP, ILSAC GF-6 and dexos1 Gen 3. Oil B declares SAE 5W-30 and API SN but does not declare the required manufacturer specification. The common viscosity does not establish equivalence for that application.
06
Two myths to avoid
“Both are 5W-30, so either is fine” is false. “Thicker always protects better” also cannot replace the engine manufacturer’s specification.
SAE indicates viscosity, not a complete approval
SAE J300 classifies engine oils by rheological requirements. In a grade such as 5W-30, “5W” relates to cold cranking and pumpability requirements, while grade 30 includes high-temperature viscosity limits. This classification does not replace the performance requirements established by API, ILSAC, ACEA or manufacturers and other organizations.
1. SAE grade
Describes the viscosity behavior required by SAE J300. It is essential information, but does not identify the correct application by itself.
2. Performance
API, ILSAC and ACEA establish test sequences and requirements involving wear, deposits, oxidation, LSPI, fuel economy and compatibility with particular systems.
3. OEM requirement
BMW Longlife, VW 50x.xx, MB-Approval, GM dexos and Ford WSS are examples of manufacturer requirements that must be checked for the specific vehicle and engine.
Vehicle + engine + market + permitted SAE grade + performance category + applicable OEM specification
Two 5W-30 oils can be technically different
Sharing an SAE grade does not establish that two oils have the same performance package, approvals or application compatibility. Professional selection therefore starts with the vehicle manufacturer's documentation, followed by checking the lubricant's actual declarations.
What to check before buying
- Identify the exact vehicle, year, engine and market.
- Check the SAE grades permitted by the manufacturer.
- Check the required API, ILSAC or ACEA category where applicable.
- Verify the required OEM specification or approval.
- Do not assume equivalence because two products share a viscosity grade.
Conclusion: “I always use 5W-30” is not a complete specification. The technically correct question is: which grade and specification does this engine require?
Technical sources
- SAE International — SAE J300: Engine Oil Viscosity Classification
- American Petroleum Institute — Engine Oil Licensing and Certification System
- ACEA — European Oil Sequences
- BMW — Engine oil information
Next · Tip 2/20
BMW Longlife
LL-01, LL-04, LL-12 FE, LL-17 FE+ and LL-22 FE++: what they mean and why viscosity alone does not establish equivalence.