The short answer: the 2018 Impala with the 2.5-liter engine requires Dexos1 Gen 2 certified 0W-20 engine oil, typically a full synthetic. This article explains the specification, capacity, and maintenance intervals to keep the car running smoothly.
The 2018 Impala’s 2.5L Ecotec engine is designed to run on a specific grade of oil that meets General Motors’ Dexos1 Gen 2 standard. Using the correct oil helps ensure optimal lubrication, fuel efficiency, and compliance with warranty requirements. Below you’ll find the exact oil type, how much you’ll need, and when to change it.
Oil specification for the 2.5-liter engine
To meet GM’s guidelines, use oil that is Dexos1 Gen 2 certified and has a viscosity of 0W-20. This is commonly sold as full synthetic, though synthetic-blend options that also meet Dexos1 Gen 2 can be acceptable if they are 0W-20.
What to use
Before you buy, confirm the product is Dexos1 Gen 2 certified and labeled 0W-20. The following options are typically acceptable:
- Dexos1 Gen 2 certified 0W-20 full synthetic engine oil
- Dexos1 Gen 2 certified 0W-20 synthetic-blend engine oil (if a full synthetic option isn’t available)
Regardless of which option you choose, avoid oils that do not carry the Dexos1 Gen 2 designation or that list a viscosity other than 0W-20, unless GM explicitly approves an alternative. When in doubt, consult your owner's manual or a GM service professional.
Oil capacity and change intervals
Understanding how much oil the engine holds and when to replace it helps you plan service visits. For the 2.5L Impala, the oil capacity is typically in the range of about 4.6 to 4.8 quarts (with filter).
- Capacity: approximately 4.6–4.8 quarts (with filter)
- Change interval: about 7,500 miles under normal driving; more frequent under severe conditions
Exact capacity can vary slightly by model year, filter type, and regional specifications. Always verify the figure on the vehicle’s oil change label or in the owner’s manual, and follow the recommended interval shown there.
Where to find definitive guidance
For the most authoritative guidance, refer to the 2018 Impala owner’s manual and the under-hood oil specification sticker. If you’re unsure, a Chevrolet dealer or certified service center can confirm Dexos1 Gen 2 0W-20 compatibility and service intervals for your specific vehicle configuration.
Additional considerations
Tips to ensure you stay aligned with GM recommendations: choose a reputable oil that meets Dexos1 Gen 2, replace the oil filter at each oil change, and use the recommended oil level and fill-to indicators shown during maintenance. If your driving is consistently in harsh conditions—extreme heat, heavy loads, or frequent short trips—the service interval may be shortened, per manual guidance.
Summary
The 2018 Impala 2.5 uses Dexos1 Gen 2 certified 0W-20 engine oil, with an approximate capacity of 4.6–4.8 quarts per change. Opt for a full synthetic (or Dexos1 Gen 2‑certified synthetic blend) and adhere to the 7,500-mile normal service interval (reducing it under severe conditions). Always verify with the owner's manual or a GM dealer if you’re unsure about the exact specification for your vehicle.