W205 Oil Selection (3) - MB Approval + LSPI Prevention 5W-30 (Part 1)

Principles of Oil Selection

Regardless of the car brand, always choose oil based on manufacturer approvals first. Once the approval is correct, you can then compare viscosity and other parameters.
For the Mercedes-Benz W205 (Gasoline), the preferred approvals remain MB 229.5 and 229.6 due to their higher TBN (Total Base Number).

LSPI (Low-Speed Pre-Ignition) and Oil Choice

Because the W205 uses a GDI (Gasoline Direct Injection) engine, it is susceptible to LSPI, which can cause cracked pistons. To prevent LSPI:

• Downshift before applying heavy throttle when cruising at high gears and low RPM.
• Oil selection is crucial: beyond just a Low-Calcium Formulation (<2000ppm), it is more important to find oils that have passed the LSPI test (Sequence IX).

Relevant Oil Approvals

• DEXOS1 GEN 2 / GEN 3: Specifically requires passing the LSPI test.
• DEXOS2:
  • Gasoline-specific oils: Require LSPI testing.
  • Combo Gasoline/Diesel oils: Do NOT require LSPI testing.
• API SN Plus: Introduced in May 2018, requires LSPI testing.
• API SP: Introduced in May 2020, requires LSPI testing and adds protection for timing chains.
• API SQ: The latest generation certification. It sets strict requirements for LSPI testing for GDI engines and significantly improves fuel economy and wear protection.
• MB 229.5 / 229.51 / 229.52 / 229.6: New approvals obtained after 2018 now require LSPI testing.

Mercedes-Approved Oils with LSPI Protection (Available in Taiwan)

The following oils meet MB approvals and have passed LSPI tests (as of 2026, always verify the latest API SP or SQ labels on the bottle):

Detailed Comparison

For a more in-depth look, please refer to this article:
MB Approved + LSPI Prevention Oils (Part 2)

Analysis: 229.5 vs 229.52

• MB 229.5: HTHS > 3.5, TBN > 10, Noack < 10%.
• MB 229.52: Requires Low-SAPS, TBN > 6.
  See my Oil Parameter Notes for more details.

Both certifications provide sufficient protection for your engine; you can choose either with confidence.

Choosing Viscosity

Some argue that viscosity should change based on driving conditions, but the engine’s operating temperature is actually fixed:

• The cooling system automatically regulates temperature whether you are in city traffic or on the highway.
• If your engine temperature rises abnormally, it indicates a failure in the cooling system, not the oil viscosity.

High-Mileage Vehicles

According to various Oil Finder websites:

• For vehicles over 75,000 miles (approx. 120,000 km), higher viscosity is often recommended:
  • Higher viscosity helps fill larger clearances caused by mechanical wear, maintaining cylinder pressure.
• Alternatively, there are High Mileage Oils:
  • These use additives to maintain a viscosity around “30” without increasing it.
  • They effectively prevent blow-by (cylinder pressure leakage) and oil leaks in older engines.
  • Reference Source

The New API SQ + MB 229.52 Era

While researching, I noticed that API SQ + 229.52 oils have been available overseas for some time. Although it is now 2026, many official distributors in Taiwan are still stuck on SP or even SN Plus products, with SQ yet to be officially imported.

Regarding parallel (gray market) importers:

• Importers sourcing from Europe and the US, who used to be ahead, are now often selling older stock—sometimes with alarming production dates.
• Japanese market importers are currently more proactive in bringing in the latest certifications. Always check the API “Donut” symbol on the bottle before purchasing.

Shell Helix Ultra X 0W-30 (China Edition) / Mobil 1 Equivalent (Visual Reference)