The 2018 Chevy Impala uses different oil specifications depending on the engine: the 2.5-liter inline-4 requires Dexos1 Gen 2 oil with a viscosity of 0W-20, while the 3.6-liter V6 uses Dexos1 Gen 2 oil with a viscosity of 5W-30. Always confirm the exact specification in your owner's manual or on the under-hood label for your specific VIN.
Engine options and oil specifications
2.5L inline-4 engine
The 2.5L four-cylinder version of the 2018 Impala is paired with Dexos1 Gen 2 oil that has a viscosity of 0W-20. This can be synthetic or synthetic blend, as long as it meets the Dexos1 Gen 2 specification.
- Oil type: Dexos1 Gen 2
- Viscosity: 0W-20
- Form: Synthetic or synthetic blend acceptable
In practice, this means you should choose a 0W-20 Dexos1 Gen 2 oil that fits your driving needs and climate, and avoid conventional 5W-30 or non-Dexos oils for this engine.
3.6L V6 engine
The 3.6L V6 in the 2018 Impala requires Dexos1 Gen 2 oil with a viscosity of 5W-30. As with the 2.5L, this oil can be synthetic or synthetic blend but must meet the Dexos1 Gen 2 standard.
- Oil type: Dexos1 Gen 2
- Viscosity: 5W-30
- Form: Synthetic or synthetic blend acceptable
Using the correct 5W-30 Dexos1 Gen 2 oil helps ensure proper lubrication, performance, and emissions compliance for the V6 engine.
Practical notes for buyers and owners
Oil capacity and change intervals vary by engine configuration and driving conditions. Always refer to the owner's manual or the under-hood oil fill label for exact specifications, capacities, and maintenance recommendations. If you’re unsure which engine your Impala has, check the VINplate or consult a Chevrolet dealer.
Summary
For the 2018 Chevy Impala, oil choice depends on the engine: 0W-20 Dexos1 Gen 2 for the 2.5L I4, and 5W-30 Dexos1 Gen 2 for the 3.6L V6. Use synthetic or synthetic-blend oils that meet Dexos1 Gen 2, and verify specifics in the owner's manual or under-hood labeling for your exact vehicle.