The 2010 Mercedes GL450 requires Mercedes-Benz approved long-life coolant that meets MB 325.0 / MB 326.0 specifications (an Organic Acid Technology, or OAT, coolant). It is typically blue and is used in a 50/50 mix with distilled water, whether you buy premixed coolant or concentrate you mix yourself.
In more detail, using the correct MB-approved coolant is essential for the GL450’s cooling system to prevent corrosion, scale buildup and overheating. If you see a label that does not reference MB 325.0 or MB 326.0, or if it isn’t an OAT formulation, it should not be used. If you’re uncertain, consult your dealer or a qualified technician to confirm the right specification for your vehicle’s production year and engine family.
Official specifications to follow
These are the core specifications you should verify on the coolant product label or in the vehicle’s service documentation.
- Type: Organic Acid Technology (OAT) coolant
- MB specifications: MB 325.0 Long-Life Antifreeze/Coolant or MB 326.0 Long-Life Antifreeze/Coolant
- Color: commonly blue or blue-green, though color alone is not a reliable indicator
- Mixing ratio: premixed 50/50 with distilled water, or concentrate to be mixed to 50/50 as directed
- Application: formulated for Mercedes-Benz cooling systems and compatible with aluminum components
Adhering to these specifications helps protect the cooling system from corrosion, prevents coolant-related deposits and ensures correct freezing/boiling protection across temperature ranges.
Practical topping up and maintenance
To keep the GL450’s cooling system healthy, follow these guidelines. The paragraphs below precede a quick-reference list of actions you can take between services.
- Verify the MB spec on the reservoir cap or service label. If in doubt, refer to the owner’s manual or MB WIS (Workshop Information System).
- Use only MB-approved long-life coolant that meets MB 325.0 or MB 326.0. Mix to 50/50 with distilled water if you’re using concentrated coolant.
- Avoid Dex-Cool or other non-MB coolants, and do not mix different coolant types in the system.
- If you need to top up, do so with the same MB-approved coolant and aim for the middle of the cold-fill range on the reservoir (with the engine cold).
- During any coolant replacement or flushing, consider a full system purge to remove air pockets and ensure proper bleed.
Following these practices helps maintain reliable engine cooling and can avert costly repairs due to improper coolant chemistry.
Summary
The 2010 Mercedes GL450 uses a Mercedes-Benz long-life coolant that conforms to MB 325.0 or MB 326.0 specifications (an OAT formulation). Look for blue, MB-approved coolant and maintain a 50/50 mix with distilled water, avoiding mixes with non-MB coolants. If you’re unsure, consult a Mercedes dealer or qualified technician to confirm the correct spec for your exact vehicle.