Proper turbocharger lubrication requires high-quality engine oil. Some oil cannot provide enough lubrication performance or durability when used in turbocharged engines. Poor-quality oil or oil not designed for turbo engines may cause damage to the turbocharger and other engine components. Consequently, it is critical to follow Subaru vehicle owner’s and service manuals for recommended oil grade and viscosity.
A second key component of the lubrication system is the oil filter. The Subaru Genuine Oil Filter, available at your Subaru dealer, is the only filter that Subaru has tested to meet requirements for filtration and flow. Aftermarket oil filters may have different filtration performance and relief-valve opening pressures, which could affect filter and engine operation. Subaru Genuine Oil Filters help ensure optimum engine and turbocharger performance.
Due to heat generated by the turbocharger and carbon deposits contained in exhaust gas, the oil in a turbocharged engine will deteriorate faster than the oil in a naturally aspirated engine. Therefore, special care should be taken to use the proper grade oil and to monitor oil deterioration.
Under normal driving conditions, the recommended oil and oil filter change interval for turbo vehicles is every 3,750 miles or four months, whichever comes first.
However, for vehicles driven in conditions beyond normal, such as racing conditions, the oil and oil filter may require more frequent changes.
Racing-type engine stress doesn’t only occur on the track. Racing-type driving takes place when the drivetrain, suspension, and other vehicle components are used at near peak capacity. Any driving where the engine speed is kept high – either by using lower gears at higher speeds or by employing engine braking – is considered racing-type driving.
Important: A “track day” or autocross event requires an oil and oil filter change immediately before and immediately after the event. Make sure to check other engine fluid levels as well.