2018 Subaru Outback Oil Change: Full DIY Walkthrough

The 2018 Subaru Outback is famous for reliability — and keeping that 2.5L or 3.6L engine healthy starts with consistently doing your own oil changes at home instead of paying $100+ at a dealer.

What You'll Need

• 0W-20 full synthetic (2.5L DOHC FB25 takes 5.1 quarts; 3.6L EZ36 takes 6.9 quarts)
• Subaru OEM oil filter: 15208AA160 (2.5L) / 15208AA170 (3.6L), or Fram PH9688 / WIX 57356
• 17mm drain plug socket or wrench
• Oil filter wrench (cap-style, 64mm for Subaru cartridge, or strap wrench)
• Drain pan (8-quart for the 3.6L)
• Floor jack and jack stands, or drive-up ramps
• Funnel
• Torque wrench
• New crush washer (Subaru part #11126AA000)

Estimated time: 30–40 minutes Estimated cost: $45–$70 (vs. $120–$160 at a Subaru dealer)

Before You Start

The 2018 Outback 2.5L has an oil consumption TSB (TSB-04-157-18R) covering certain build dates — Subaru extended oil consumption monitoring for some customers. If you're going through more than 1 quart per 1,000 miles, document it and contact Subaru. Also note: the Subaru FB25 engine requires a Subaru-spec full synthetic — Subaru Synthetic 0W-20 or equivalent meeting ILSAC GF-5 or GF-6 standard. Subaru recommends an oil change interval of 6 months or 6,000 miles (conventional) or 12 months/6,000 miles (full synthetic with standard driving). With the OEM Subaru filter, Subaru approves up to 6,000 miles.

Step-by-Step Instructions

1. Warm the engine briefly — 5 minutes. Warm oil flows faster and carries more suspended contaminants out of the sump.
2. Raise and support the car — The Outback has good ground clearance. Ramps work well. If using a floor jack, lift from the front crossmember and use jack stands.
3. Locate the drain plug and filter — The 17mm drain plug is at the rear of the oil pan on the 2.5L. The oil filter on the 2.5L is a spin-on filter on the driver's side of the engine, accessible from underneath.
4. Position the drain pan and remove the drain plug — Account for the oil stream arcing forward. Use the 17mm socket, break it loose, then spin out by hand. Step aside as oil flows.
5. Remove the oil filter — Use the oil filter wrench to break it loose, then spin off by hand. Some oil will drip — have rags ready.
6. Let it drain fully — The 2.5L sump drains in about 5 minutes. Don't rush — the last 10% matters for cleanliness.
7. Install the new filter — Lightly coat the new filter gasket with fresh oil. Hand-tighten until the gasket contacts the engine, then turn an additional 3/4 turn. No wrench needed.
8. Replace the drain plug with a new crush washer — Thread in by hand, then torque to 33 ft-lbs (44 Nm) on the 2.5L. The Subaru spec is firm — match it precisely.
9. Add fresh oil — Pour in 4.8 quarts of 0W-20 for the 2.5L. Check the dipstick, then add remaining oil to reach the FULL mark (approximately 5.1 quarts total).
10. Run the engine and inspect — Start the engine and check the oil pressure light extinguishes within 5 seconds. Let it run 30 seconds, shut off, wait 2 minutes, then re-check the dipstick and look for leaks.
11. Reset the oil change indicator — With the ignition on (engine off), press the Trip button on the instrument cluster until "Oil" or "Maintenance" appears. Hold the reset button for 3–5 seconds until it clears.

Common Mistakes to Avoid

• Not checking for oil consumption between changes — The 2018 Outback 2.5L has a documented oil consumption tendency. Check the dipstick monthly; don't just wait for the Maintenance Reminder.
• Using conventional oil — Subaru's FB25 benefits significantly from full synthetic. Conventional oil at the 6,000-mile interval is acceptable but leaves performance on the table.
• Skipping the crush washer — The Subaru drain plug uses a soft copper crush washer. Reusing it risks a slow weep at the drain plug. At $1–$2 each, there's no reason to skip it.
• Over-torquing the drain plug — 33 ft-lbs is spec. The oil pan on the Outback is aluminum; over-tightening strips the drain hole.

Troubleshooting

Oil consumption greater than 1 qt/1,200 miles: Check Subaru's TSB-04-157-18R. If your VIN falls in the covered range, contact Subaru Customer Service. Some affected vehicles received warranty extensions for piston ring replacement.

Oil pressure warning light flickers on cold start: Usually a pressure relief valve or pickup tube sludge issue from extended intervals with conventional oil. Switch to full synthetic and change more frequently (5,000 miles) to see if it clears.

Drain plug weeping after torque: Replace the crush washer with a new Subaru OEM part (#11126AA000). Generic washers sometimes don't conform correctly to Subaru's thread pitch.

Final Thoughts

Staying on top of oil changes is the single most important thing you can do for the long-term health of your 2018 Subaru Outback — especially given the documented oil consumption tendency of the FB25. DIY makes this faster, cheaper, and keeps you in tune with your car's condition. For the complete Outback maintenance guide covering CVT fluid, spark plugs, and timing chain service, see the OwnerDrop Complete DIY Mechanic Library.

---

Want the complete step-by-step system for maintaining your 2018 Subaru Outback? The Complete DIY Mechanic Library covers oil changes, brakes, electrical, suspension, and more — everything in one place.