Subaru Dials Back Engine Oil Change Interval for 2015 Model Year

Currently for all 2014 Subaru vehicles, the car maker recommends changing the engine oil for every 7,500 miles (this is the minimum requirement).

But we have got confirmation from our Subaru source that, the manufacture will reduce the mileage number to 6,000, starting for all 2015 model year Subaru vehicles.

Different from most of other auto makers, Subaru uses horizontally opposed-cylinder engine (called “boxer engine”) in its cars.  This type of engine has low center of gravity, which benefits the car’s handling. But this comes with expense that other V-shaped or I-shaped engine don’t have.

For example, because the cylinders are lying flat in the engine bay, the engine’s head gasket is immersed in the engine oil and also the coolant. Therefore the gasket will corrode more rapidly than other traditional engines, whose head gasket is not immersed in those liquids. For this reason, in some models Subaru installed sponges beneath the engine head gasket area to absorb the leaked oil. Another example is because of the gravity force, the lower part of the piston ring tends to receive more engine oil than the upper part, which causes uneven lubrication effect of the engine piston rings.

So for Subaru cars, it is good to change the engine oil more frequently. Unlike some auto makers that claim to have engine oil change interval well exceeding 10,000 miles, from my point of view the decision Subaru makes actually benefits its users.

Although someone may cite some UOA (used oil analysis) results to show it is still safe to change oil for xxxx miles, let’s not forget these facts: 1. from business aspect, what an auto maker really cares is to let your car run fine during the warranty period; 2. it is very hard to prove the engine piston ring/valvetrain wear is fully due to long oil change interval set by car manufacturer, this means it require great effort for you to claim warranty; 3. for some brands that cover all maintenance cost during warranty period, the less frequent the car requires engine oil change, the less cost for the car manufacturer.

I am not saying the oil change interval set by any car manufacturer is not correct. My point is: based on your user manual recommendations, you can treat your car better by exceeding the minimum requirements.