Subaru replaced the EJ25 with the FB25 in 2011 - and ran headfirst into a different problem. The new piston ring design caused excessive oil consumption (some owners reporting 1qt per 1,500 miles or worse) on 2011-2014 Forester, Outback, Legacy, Impreza, and Crosstrek. After class-action litigation, Subaru issued ECM updates, extended warranties, and even buyback options. Here's the full picture.
A class action covering 2011-2014 FB25 vehicles was settled in 2016. If you own one, your VIN may be eligible for a free engine repair, ECM update, or buyback - check with Subaru of America.
The factory piston rings allow oil past the rings into the combustion chamber. Many owners report burning a full quart every 1,500-2,000 miles. Subaru's settlement covers ring replacement on documented cases.
Get help with my FB25 →The 2016 settlement extended the engine warranty to 8 years or 100,000 miles on affected FB25 vehicles, required Subaru to perform a free oil consumption test on demand, and made buyback an option for repeat-failure cases.
Get help with my FB25 →Heavy oil consumption fouls spark plugs and triggers misfire codes (P0301-P0304). Replacing plugs without addressing rings is a temporary fix.
View P0301 Diagnosis →Subaru issued an ECM reflash that adjusts fuel trims and oil consumption monitoring. Helps marginal cases but does not fix worn rings.
Run free diagnosis →Long-term oil consumption coats the cat substrate and triggers P0420. Sometimes covered under emissions warranty depending on state and mileage.
View P0420 Diagnosis →FB25 oil consumption usually shows no blue smoke at the tailpipe - the oil burns slowly and cleanly. Don't use "no smoke" as proof the engine is healthy.
Run free diagnosis →Run a free AI diagnosis tailored to your exact Subaru FB25. Get the most likely cause and repair estimate in under 30 seconds.
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2011-2014 Forester, Outback, Legacy, Impreza, and Crosstrek with the FB25 unless the rings have been replaced under the class action.
2015+ FB25 (improved piston rings) and 2019+ FB25 in the redesigned Forester are clearly better. 2014.5+ Outback also got the updated rings.
If your VIN is covered, a Subaru dealer will perform a free oil consumption test and replace the short block under the extended warranty. Out of warranty, a piston ring job runs $2,500-$4,000.
If your Subaru FB25 is throwing a check engine light, these codes are most associated with the problems above. Click any code for full diagnosis steps and typical repair costs.
Yes - Yaeger v. Subaru of America was settled in 2016. It extended the FB25 engine warranty to 8 years or 100,000 miles on affected 2011-2014 vehicles, mandated a free oil consumption test on request, and offered buyback for chronic cases.
Affected engines commonly burn 1 quart per 1,500-2,000 miles. Subaru's threshold for warranty repair under the settlement was 1qt per 1,200 miles documented across two consumption tests.
For documented cases the dealer replaces the short block (pistons, rings, bearings) under the extended warranty. For marginal cases an ECM reflash and continued monitoring is the first step.
2011-2014 Forester, Outback, Legacy, Impreza, and Crosstrek with the 2.5L FB25 are the affected models. 2015+ engines have updated rings and are far less affected.
No - the issue is mechanical (ring tension and design). Additives may slow consumption marginally but will not restore ring seal.