If you are new to Subaru vehicles or would like to know more about the crucial maintenance needed, these are some tips from a variety of posts I've made on various forums put together on this thread.
Please note that these tips are from the perspective of an owner/driver in North America. If you live and/or have a Subaru vehicle of a specification outside North America, there may be some differences.
I strongly suggest you read them and keep them in mind as these tips could save you from potentially replacing expensive components that would otherwise be in serviceable condition if they had been maintained and treated properly.
DISCLAIMER: Although I strive for the information I've provided to be as accurate as possible, I cannot guarantee that it is 100% correct. I am not responsible for any damages that one may believe to be a result of following advice I've provided. ALWAYS consult your vehicle's correct OWNER'S MANUAL and/or manufacturer representative for the most accurate and up-to-date information.
1) If this is your first Subaru, it is best to rely primarily on OEM engine oil filters only, or aftermarket engine oil filters that legitimately meet the OEM specs.
Engine oil/motor oil specifications (your vehicle may vary, so verify in YOUR VEHICLE'S owners manual)
Any fully synthetic motor oil meeting the following specs should be used.
API (American Petroleum Institute) classification
SM with the words "ENERGY CONSERVING" or SN with the words "RESOURCE CONSERVING"
ILSAC (International Lubricant Specification Advisory Committee)
GF-4 or GF-5, which can be identified with the ILSAC certification mark (Starburst mark)
meeting the SAE (Society of Automotive Engineers) engine oil viscosity rating of
0W-20 (if vehicle is used in North America of a North American country's specifications)
SAE viscosities 5W-30 and 5W-40 may also be used (regardless if synthetic or conventional) meeting the above API or ILSAC specs, but Subaru recommends 0W-20.
There is an abundance of engine oils that meet the specs outlined in the owner's manual, but oil filters that meet Subaru's unusually high bypass valve spec are few.
Some of the ones I know that meet the spec for the FB engines are (but this list may not be complete)
- Subaru blue OEM (manufactured by Honeywell/FRAM in USA and Canada) P/N 15208AA15A
- Subaru black OEM (manufactured by Tokyo Roki, highly sought after; Made in Japan) P/N 15208AA160
- Six star brand (Canadian OEM, manufactured by Northeast Imported Parts, Inc. in Thailand) NEIP does not sell to general public or "consumer market", only sells to fleet, buisnesses, and companies. Do NOT call NEIP unless you are representing a fleet, business, or company! P/N 15208AA100, 15208AA060A (both filters are not confirmed applications)
- Killer Filters (OEM filters for certain Subaru of America part numbers, currently does not manufacture engine oil filters for Subaru FB engines)
- Purolator oil filters (Made in USA, former Subaru OEM for white genuine Subaru engine oil filters) P/N L14615, PL14615
- Wix oil filters P/N 57830 (shorter, wider; substitutes Subaru 15208AA160), 57055 (narrower, taller; substitutes Subaru 15208AA15A)
- pink STI (Subaru Tecnica International, prohibitively expensive, used by motorsport teams especially Subaru factory rally and race teams; Made in Japan) P/N ST15208ST000
Most generic aftermarket oil filters will have a low bypass valve pressure spec as most engines use such a specification. Subaru's boxer engines are different in that they require a higher bypass valve pressure specification.
If an aftermarket filter not meeting OEM specs is used, this may result in the engine oil bypassing the oil filter, essentially running unfiltered engine oil throughout your engine's oil system in a manner that Subaru's engineers did not intend to.
This is why the OEM specification for the engine oil filter is crucial for the operation and longevity of your Subaru's boxer engine.
2) Monitor your tire pressures religiously and when replacing tires, replace ALL FOUR main service tires* ALL AT ONCE.
* In this part of this post, "main service tire" is a reference to the tires designed to be the primary service tire, which excludes the spare tire.
It is best to check them when cold for maximum accuracy. Subaru defines cold tires as being driven less than 1 mile and having sat for more than 3 hours.
Your tire pressure specifications can be found at your driver side doorjamb, which are the pressures specified when the tires are cold. Your tire specifications are NOT necessarily the maximum pressures specified at the tire.
The owner's manual calls for a monthly checkup.
I go a step further and check all four main service tires once a week. (I would recommend this if you drive a lot of miles). I check the spare tire once a month, in line with the owner's manual recommendation.
Ensure that you are checking all FIVE (5) tires of your vehicle, which includes the often-neglected spare tire.
As I will explain below, the following three aspects should be kept in mind:
- Tire Pressure
- Tire Wear and Tire Wear Patterns
- Suspension Alignment Angles
Because the center differentials are the very basis of the AWD system, they need to be treated with care. It is absolutely imperative that owners/drivers maintain their main service tire pressures, tire wear, and keep their suspension alignment in good order to fully prolong the AWD system's driveline components. As I have found out the hard way with my previous Subaru, the center differential can be surprisingly sensitive to slight differences many uninformed or new-to-Subaru drivers would deem acceptable.
Thankfully, we in North America get an All-Wheel Drive warning light (which I call the "AWD idiot light") for Lineartronic CVT models that blinks if the vehicle is driven with tires of differing diameters fitted on the wheels (which can occur with an excessively low air pressure in any of the drive tires, severely uneven tire wear, etc), while manual transmission models have no such light to inform the driver of a significant difference between tires.
This difference, as defined by Subaru of America, is a circumference difference of more than 1/4 inch between main service tires, which is deemed unacceptable.
A circumference difference of less than 1/4 inch between tires is acceptable.
The manufacturer of your vehicle (in this case, Subaru of course) has specified main service tire pressures so as to optimize their desired target performance for a variety of factors. But most importantly of all, the main service tire pressures specified are designed to prolong the life of the center differential of your AWD system. Ignoring the manufacturer specifications may (and in my case for my first Subaru) and will result in the eventual failure of the center differential, a costly repair.
I go the extra step and ensure the main service tires are uniformly exposed or shielded from sunlight and the vehicle set at a level surface such as a garage.
The reason why I preach this is because the lack of tire maintenance on my first Subaru resulted in a failing center differential and a driveline that was basically ready for the junkyard. It is a good idea to err on the side of caution and periodically check your tire wear patterns and inspect the suspension alignment angles.
A bad alignment can snowball from a slight inconvenience, to unevenly worn tires, to eventual driveline component damage. Ensure your suspension alignment is inspected by professionals with precision equipment, as suspension alignment isn't something that can be done exclusively with the naked human eye. It requires precision tools for such an inspection.
Tire rotations are absolutely crucial
, as failure to rotate the main service tires can and will cause uneven tire wear between all four main service tires and can eventually lead to AWD system damage and failure. This is likely the biggest tire maintenance mistake I made on my first Subaru, as the front tires were balded while the rear tires had very high tread remaining. Needless to say, this significant disparity between the front and rear main service tires fast-tracked the failure of my AWD system's center differential. Follow the tire rotation interval as specified in your vehicle's service schedule. If you drive under unusual and/or severe conditions, consider rotating your tires at a shorter interval, at maybe half the mileage of the regular rotation interval.
Although I recommend running the specified tire pressures on your tire placard at the driver doorjamb, if you're adamant on running higher pressures, I'd advise to use the same front-to-rear proportion of pressure as the specified pressures on the placard.
Avoid running the spare tire for a long period of time as it is intended only for temporary use. As you have read above, it is not a good idea to drive with the spare for very long due to the difference in circumference. Replace the bad main service tire(s) as soon as possible, and refer to the paragraphs below this paragraph for more information.
When using the spare tire, install the spare tire at the rear wheel only.
If a front main service tire failure occurs, replace the bad front main service tire with a good rear main service tire and place the spare tire where that rear main service tire was previously mounted. And don't forget that you should not exceed 50 MPH (80 KMH) when driving with the spare tire mounted.
Tire replacement requires replacement of ALL four main service tires
. As you should know after reading the above, the circumference of all main service tires must be very close to each other and replacing any less than all four main service tires is in almost all cases almost certainly going to cause eventual damage to your AWD system, most especially the center differential.
When replacing the main service tires, as the owners manual indicates, all four tires must be the same in terms of manufacturer, brand (tread pattern), construction, and size. Ensure the replacement main service tires have the same exact UTQG (Traction, Treadwear, Temperature ratings) as a same-size, same model tire can still have different UTQG ratings. Most importantly, verify the new replacement main service tires have speed and load ratings that meet or exceed the OEM specifications.
However, if you are unable to purchase all four main service tires and can only replace a limited number of tires, there is the option of shaving the tires down at the tire tread to equal circumference, which is not a recommended service. Small tire shops, typically those popular with performance car enthusiasts who do autocross, track days, etc will very likely offer this service. Do note that shaving tires to equal circumference may void your tires' warranty.
Also, I recommend you do not ignore your TPMS light
if it is illuminating and the TPMS was previously functioning normally. Do not automatically assume that your sensors are faulty, check the pressures on all four main service tires
. Do note that with warm tires, pressures will be higher than the specifications. Any significant disparity between tires may be an indicator of a tire leak in one or more tires.
A visual inspection is insufficient at judging whether tires are truly underinflated when inspecting the main service tires after the low tire pressure warning lamp illuminates.
I myself have made this mistake of not trusting the light only to find out I had driven over 240 miles on one main service tire low on pressure. It turned out I had a nail in one of my main service tires and ran it underinflated. Thankfully, it was repairable. However, repaired tires may no longer support the speed and load ratings they were rated at when new and the original tire warranty may be void.
3) Before you begin your day driving your vehicle, consider doing a pre-drive inspection every day before you begin driving according to the owner's manual, as well as inspections during fuel stops.
The pre-drive inspection takes me less than 2 minutes to perform, which I typically do every morning.
The fuel stop inspection takes me less than 5 minutes to perform, which I typically do after I've filled the fuel tank to full.
For my 5-speed manual 2014 Crosstrek, I put this on my sunvisor's map hold as a reminder (your vehicle's setup of warning lamps may vary, CHECK YOUR VEHICLE'S WARNING LAMPS TO PROPERLY CONFIGURE YOUR OWN PICTURE)
I have transcribed the text from the owner's manual in the image just in case of a failure of the picture to appear.
Preparing to drive
You should perform the following checks and adjustments every day before you start driving.
- Check that all windows, mirrors, and lights are clean and unobstructed.
- Check the appearance and condition of the tires. Also check tires for proper inflation.
- Look under the vehicle for any sign of leaks.
- Check that the hood and trunk lid are fully closed.
- Check the adjustment of the seat.
- Check the adjustment of the inside and outside mirrors.
- Fasten your seatbelt. Check that your passengers have fastened their seatbelts.
- Check the operation of the warning and indicator lights when the ignition switch is turned to the "ON" position.
- Check the gauges, indicator and warning lights after starting the engine.
When checking the tires, a quick scan of the tread and a kick on each tire should suffice for your daily inspection.
In addition, checking all fluids according to the owner's manual is something that should be done during every fuel up.
According to the owners manual, these are the services that should be done during fuel ups.
should be checked daily, weekly or at fuel stops.
- Engine oil
- engine coolant
- brake fluid
- washer fluid
- and other fluid levels
The pre-drive inspection and fuel stop inspections become even more crucial during long trips.