High Oil Consumption on my 2017 Forester 2.5i

ClearTheCode admin answer:

Excessive oil consumption in Subaru's 2.5L FB series engines (which your 2017 Forester has) was a known issue for certain model years, though generally less prevalent than in the older EJ series. While some oil consumption is normal for any engine, a quart every 2,000-2,500 miles is on the higher side and warrants investigation.

Here's what you should do:

1. Start an Oil Consumption Test: The most definitive way to diagnose this is to have a Subaru dealership perform an official oil consumption test. They will top off your oil, seal the dipstick and oil fill cap, and have you return after a specified mileage (usually 1,000-1,200 miles) to measure the consumption. This provides documented evidence for potential warranty claims.
2. Check PCV Valve: A clogged or faulty PCV (Positive Crankcase Ventilation) valve can lead to increased oil consumption by not properly venting crankcase pressure, which can force oil past piston rings or valve seals. This is a relatively inexpensive part to inspect and replace.
3. Inspect for External Leaks: Even if you don't see drips, check for oil residue around the valve covers, timing chain cover, and oil pan. Sometimes leaks are minor and burn off before hitting the ground.
4. Consider Oil Type: Ensure you are using the correct viscosity oil (typically 0W-20 synthetic for your engine) as specified by Subaru. Using a different viscosity can sometimes affect consumption.
5. When to See a Shop: Schedule an appointment with your Subaru dealership to initiate the oil consumption test. If the test confirms excessive consumption, Subaru may offer repairs under an extended warranty or goodwill, depending on the specific cause (e.g., piston rings, valve guides). Do not delay, as prolonged excessive consumption can lead to engine damage if oil levels are not consistently monitored and topped off.