The GL450 from 2008 uses a synthetic oil that meets Mercedes-Benz specification MB 229.5, typically in a 0W-40 or 5W-40 viscosity. Oils with this approval are widely available; always verify the bottle label or with a dealer to confirm MB 229.5 approval.
Recommended oil specifications
To ensure proper lubrication and maintain warranty requirements, use a synthetic motor oil that meets MB specification 229.5. The GL450's 4.7-liter V8 prefers long‑life lubricants, and the viscosity choice depends on climate and driving conditions.
- MB specification: MB 229.5 (or newer MB 229.51) — the standard long‑life oil specification for this engine.
- Viscosities commonly used: 0W-40 or 5W-40 synthetic oils that meet MB 229.5.
- What to avoid: conventional mineral oils or oils tied to older MB specs not approved for this engine.
- Approved oil examples (availability varies by market): synthetic oils labeled as 0W-40 or 5W-40 with MB 229.5 approval on the bottle.
Using an MB 229.5-approved oil in a 0W-40 or 5W-40 viscosity range supports proper lubrication, performance, and the long‑life service intervals typical of this Mercedes generation.
Climate-driven considerations
Oil viscosity should align with climate and driving style while staying within MB 229.5 approval. The following guidance helps readers select the right grade for their conditions.
- Cold climates: 0W-40 synthetic oil that meets MB 229.5.
- Moderate to hot climates or frequent highway driving: 5W-40 synthetic oil that meets MB 229.5.
- Heavy towing or extreme heat: maintain MB 229.5 approval and consider 5W-40 for stronger film strength.
The core requirement is to choose a synthetic oil with MB 229.5 approval and select a viscosity appropriate for your climate and usage.
Summary
For the 2008 Mercedes GL450, the recommended oil is a synthetic oil that meets Mercedes-Benz MB 229.5 specification, with 0W-40 or 5W-40 being the typical viscosities. Always verify the exact spec in the owner's manual or with a Mercedes service professional and ensure the bottle clearly lists MB 229.5 approval.