The 2018 Subaru Impreza is a popular choice for drivers seeking reliability, all-wheel-drive capability, and a comfortable ride. Like any vehicle, proper maintenance is crucial for its longevity and performance, and understanding its oil capacity and the correct type of oil to use is fundamental. Using the right oil ensures optimal engine lubrication, fuel efficiency, and protection against wear and tear, especially given Subaru’s unique Boxer engine design.
Understanding Your 2018 Subaru Impreza Engine
The 2018 Subaru Impreza models available in the US and Canada are powered by a 2.0-liter, naturally aspirated, four-cylinder Boxer engine. This horizontally opposed engine design is a Subaru hallmark, known for its lower center of gravity, which contributes to the Impreza’s stable handling. This engine is designed to be efficient and reliable, but it relies heavily on the correct lubrication to perform at its best.
2018 Subaru Impreza Oil Capacity
Knowing the exact 2018 Subaru Impreza oil capacity is vital for anyone performing an oil change or simply topping up their engine. For the 2.0L DOHC (Double Overhead Cam) engine found in the 2018 Impreza, the recommended oil capacity is:
4.2 US Quarts (4.0 Liters) with a filter change
It’s critical to ensure you’re using a precise measurement when adding oil. Overfilling can be just as detrimental as underfilling. Too much oil can cause aeration, leading to reduced lubrication efficiency and potential damage to engine seals. Too little oil, conversely, will lead to insufficient lubrication, increased friction, and accelerated engine wear, potentially causing catastrophic engine failure.
Always check your oil level on a flat surface after the engine has been turned off for at least 5-10 minutes, allowing all the oil to drain back into the oil pan. The dipstick has clear “full” and “add” markers, and your goal is to have the oil level squarely between these two points, ideally closer to the “full” mark.
Recommended 2018 Subaru Impreza Oil Type
Subaru is very specific about the type of oil to use in its vehicles, and the 2018 Impreza is no exception. For optimal performance, fuel economy, and engine protection, the manufacturer strongly recommends:
SAE 0W-20 Full Synthetic Motor Oil
This recommendation isn’t arbitrary; it’s based on extensive engineering and testing. Here’s why 0W-20 full synthetic is the preferred choice:
1. Viscosity (0W-20): The “0W” indicates excellent cold-weather performance. The oil remains thin and flows easily at low temperatures, ensuring rapid lubrication during cold starts – a time when most engine wear occurs. The “20” refers to its viscosity at operating temperature, providing adequate protection without creating excessive drag, which aids in fuel efficiency.
2. Full Synthetic Formulation: Full synthetic oils are engineered to offer superior protection compared to conventional or synthetic blend oils. They have a more uniform molecular structure, which means better resistance to breakdown under high heat and stress, cleaner engine operation (less sludge), and improved lubrication properties. This is especially important for modern engines with tighter tolerances and higher operating temperatures like the 2.0L Boxer engine.
3. API and ILSAC Certifications: Ensure the oil you choose meets the latest industry standards. Look for oils displaying the API (American Petroleum Institute) “Starbust” symbol, indicating it meets current service requirements (e.g., API SN Plus or SP). Also, look for the ILSAC (International Lubricant Specification Advisory Committee) GF-6 certification, which denotes improved fuel economy, engine cleanliness, and wear protection.
Using anything other than 0W-20 full synthetic could compromise your engine’s long-term health, affect fuel economy, and potentially void your warranty if an engine issue related to improper lubrication arises.
The Importance of Quality Oil and Regular Changes
Adhering to the correct oil type and capacity is just one part of the equation. Regular oil changes with high-quality oil are paramount for the 2018 Impreza.
Engine Protection: Fresh oil contains detergents and anti-wear additives that protect internal engine components from friction, corrosion, and deposits. Over time, these additives break down, and the oil becomes contaminated with combustion byproducts.
Fuel Economy: Clean, fresh oil with the correct viscosity reduces friction, allowing the engine to run more efficiently, thus improving fuel economy.
Engine Longevity: Regular oil changes prevent sludge buildup and excessive wear, extending the life of your engine, which is often the most expensive component to repair or replace.
Subaru generally recommends oil changes every 6 months or 6,000 miles (10,000 km), whichever comes first, for normal driving conditions. However, if you frequently drive under severe conditions (e.g., extreme temperatures, heavy stop-and-go traffic, towing, dusty roads), more frequent changes might be necessary. Always consult your owner’s manual for the most accurate and up-to-date service intervals for your specific driving habits.
DIY Oil Change Considerations
For the experienced DIY enthusiast, changing the oil on a 2018 Subaru Impreza can be a rewarding task. Remember to:
Gather the right tools: Wrench for the drain plug, oil filter wrench, funnel, drain pan, jack stands (and jack), and gloves.
Prioritize safety: Always use jack stands to secure the vehicle when working underneath it. Ensure the engine is warm but not scalding hot.
Dispose of old oil responsibly: Never pour used motor oil down the drain or into the trash. Most auto parts stores and service stations offer free oil recycling.
Conclusion
Maintaining your 2018 Subaru Impreza properly involves understanding and adhering to its specific requirements for engine oil. By using the recommended 4.2 US quarts of SAE 0W-20 full synthetic motor oil and following Subaru’s suggested oil change intervals, you’ll ensure your Boxer engine runs smoothly, efficiently, and reliably for many years and miles to come. Always refer to your vehicle’s owner’s manual for the most precise and comprehensive information.
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Source:
* 2018 Subaru Impreza Owner’s Manual