The 2018 Chevy Malibu uses Dex-Cool orange long-life coolant, the GM Dex-Cool/OAT formulation. It should be mixed 50/50 with distilled water unless you buy pre-diluted Dex-Cool, and you should avoid mixing it with conventional green coolant.
Dex-Cool is designed for GM engines with aluminum cooling systems and helps protect against corrosion and overheating. Using the correct type and mix is important for the Malibu’s cooling system; this article outlines the right coolant, how to identify it, and practical maintenance tips.
Coolant type for the 2018 Malibu
Use Dex-Cool orange long-life coolant, GM specification Dex-Cool (often listed as GM 4718M or Dex-Cool OAT). The Malibu’s cooling system is designed for this orange coolant, and using a different type can lead to deposits, corrosion, or coolant incompatibilities.
- Dex-Cool (orange) long-life coolant, GM Dex-Cool / OAT, typically sold as Dex-Cool or GM 4718M.
- Do not mix with conventional green coolant or other non-Dex-Cool formulations.
- Mixing rule: 50/50 with distilled water, unless you purchase a pre-diluted Dex-Cool product.
- Color identifier: orange coolant; keep at the correct fill level in the reservoir and radiator neck as recommended.
- Replacement interval: about every 5 years or 150,000 miles, per GM maintenance guidelines or your owner's manual.
- Top-off guideline: if you need to add coolant between changes, only add Dex-Cool to preserve the system’s chemistry.
Maintaining the correct Dex-Cool balance helps prevent corrosion, overheating, and potential cooling-system failures in the Malibu’s aluminum engine.
Maintenance tips and practical steps
When replacing or topping off Dex-Cool, follow these practical steps to protect the cooling system.
- Ensure the engine is cool before opening the cooling system to prevent burns from hot coolant or steam.
- Verify you’re using Dex-Cool (orange) coolant; confirm the product label matches GM Dex-Cool/OAT specification.
- Use a 50/50 mixture of Dex-Cool and distilled water unless you’re buying pre-diluted Dex-Cool; do not use tap water.
- If performing a full flush, consider following the factory service procedure or dealership guidelines to avoid residual old coolant mixing with new Dex-Cool.
- Reconnect hoses and fill via the reservoir until the level sits between the "MIN" and "MAX" marks; replace the radiator cap securely and run the engine to circulate and purge air.
Following these steps helps ensure the system remains free of air pockets and that the Dex-Cool remains properly mixed for optimal cooling performance.
Summary
For a 2018 Chevy Malibu, use Dex-Cool orange long-life coolant (GM Dex-Cool/OAT), typically in a 50/50 mix with distilled water. Never mix it with green coolant, and adhere to the recommended replacement interval and topping-off guidelines to protect the engine’s cooling system.