The 2018 Subaru Outback uses 0W-20 synthetic oil for the 2.5-liter engine and 5W-30 synthetic oil for the available 3.6-liter engine. Both should meet current API/ILSAC standards and be synthetic.
The oil specification you need depends on which engine your Outback has. Subaru offered two powertrains for the 2018 model year: a standard 2.5-liter flat-four and an optional 3.6-liter flat-six. Understanding the correct viscosity and specifications helps maintain warranty coverage and engine longevity.
Oil types by engine
The following breakdown clarifies which oil to use based on the engine in your 2018 Outback.
- Engine: 2.5-liter FB25 four-cylinder. Oil: 0W-20 synthetic oil recommended by Subaru, meeting API SN/SN+ and ILSAC GF-5 or GF-6 standards.
- Engine: 3.6-liter EZ36 flat-six. Oil: 5W-30 synthetic oil recommended by Subaru, meeting API SN/SN+ and ILSAC GF-5 or GF-6 standards.
Note: If you cannot source 0W-20, consult your dealer or the owner’s manual for acceptable alternatives, but stay within the engine’s specified viscosity range and consider synthetic oils to preserve performance and warranty.
Oil capacity and service considerations
Knowing how much oil your engine holds and how often to replace it helps keep the Outback running smoothly and efficiently.
2.5-liter engine capacity
The 2.5L engine typically takes about 4.5 quarts (approximately 4.3 liters) of oil with a filter change.
3.6-liter engine capacity
The 3.6L engine holds roughly 6.5–7 quarts (about 6.2–6.6 liters) with a filter, depending on the exact variant and filter used. Always verify the precise specification for your VIN in the owner’s manual or service guide.
Oil type and capacity are essential for engine longevity. Use fresh synthetic oil that meets Subaru’s specifications and replace the filter with every oil change.
Practical tips for owners
Here are practical notes to help you choose the right oil and stay on track with maintenance.
- Use synthetic 0W-20 for the 2.5L engine, or synthetic 5W-30 for the 3.6L engine, as specified by Subaru.
- Choose oils that meet API SP or SN and ILSAC GF-5 or GF-6 standards.
- Prefer Subaru Genuine oil or equivalent from reputable brands that are approved for Subaru engines.
Regular oil changes are key to performance and emissions control. If you regularly drive under severe conditions (extreme temperatures, frequent short trips, towing), consult the manual or a dealer for any adjusted intervals.
Summary
In brief, the 2018 Subaru Outback requires 0W-20 synthetic oil for the 2.5L engine and 5W-30 synthetic oil for the 3.6L engine, with capacities around 4.5 quarts for the 2.5L and roughly 6.5–7 quarts for the 3.6L. Always verify the exact specification for your vehicle in the owner’s manual or with a Subaru dealer.
Overall takeaway: engine variant dictates oil viscosity; use synthetic oil that meets current standards; consult the manual for exact capacities and service intervals; and choose quality oils approved for Subaru engines.