There's a disconnect between what people think a car needs, and what the official maintenance schedule says.

For warranty purposes, follow the official maintenance schedule. Your warranty itself runs out based on time or miles, whichever comes first.

I recently posted the schedule and how to interpret it:

https://www.subaruoutback.org/threads/cvt-fluid-change-at-60k-miles.563529/post-6443380

 

Yep, for every new car that I have ever owned it has always been "whichever comes first".

Something like the tire rotation is really only affected by miles not months, but I alway do it at the same time I do the oil. Otherwise if you pick and chose for certain items, it get too complicated to keep track of when everything is due.

And as others had said, doing it a little early before it is due is always a good thing.

 

Hi. Sorry if this has been addressed. Searched the forums and didn't see my question ...

I've owned my 2023 OBW since March of 2023. Did a service at 6 months (oil change / tire rotation + whatever else gets checked at that stage).

Now, I'm coming up on 12 months and when I called to schedule service there was some confusion regarding 12 months vs 12,000 miles. They want to do a 12,000 mile service but I have less than 8,000 miles on the vehicle.

This is the first new car I've purchased in 30 years and I'm not certain the best way to tick all the service items required to stay in warranty. I also have the 10/100,000 extended plan.

What schedule should I follow? Time or Mileage? I don't have the manual in front of me here at work, but I thought it had monthly designations (but maybe it was mileage).

TIA for any advice.

The maintenance schedule for most vehicles, including Subaru, indicates months or miles, whichever comes first.

 

Hmm. That could be an issue. Looking ahead a few years down the road ... say, for example, 3 years from now, at the 4 yr / 48 month mark, I have 25,000 miles on the car, the maintenance schedule is going to be way ahead of the actual mileage and some wear & tear items are not going to be needed.

I need to look at the manual again when I get home to talk more intelligently about this. My apologies. I should have had it in hand before starting this conversation.

 

Hi. Sorry if this has been addressed. Searched the forums and didn't see my question ...

I've owned my 2023 OBW since March of 2023. Did a service at 6 months (oil change / tire rotation + whatever else gets checked at that stage).

Now, I'm coming up on 12 months and when I called to schedule service there was some confusion regarding 12 months vs 12,000 miles. They want to do a 12,000 mile service but I have less than 8,000 miles on the vehicle.

This is the first new car I've purchased in 30 years and I'm not certain the best way to tick all the service items required to stay in warranty. I also have the 10/100,000 extended plan.

What schedule should I follow? Time or Mileage? I don't have the manual in front of me here at work, but I thought it had monthly designations (but maybe it was mileage).

TIA for any advice.

Subaru and your service department want you to use the "whichever comes first" method. I use a blended method. I'm not saying it's the best method but it is my method. For anything involving fluids (oil, gas, brake fluid, differential oil, etc.) I follow the whichever comes first method. However, for most other things (spark plugs, tire rotation, engine air filter, etc.) I generally only use mileage as a reference regardless of time.

I do this because I drive my Outback significantly less than average so, for example, I won't replace my spark plugs at 60 months because I'll only have around 30K mikes on the vehicle at that time (December 2024). I'll probably wait at least a couple of more years to do that.

For most people who put average mileage on their vehicles, the "whichever comes first" method is probably the best approach to take because time/mileage will more closely align.

 

Ok. I'm embarrassed (been a long week). Just pulled the manual and looked again. The info is there, I just didn't register it correctly. It is either or (miles vs time).
But thank you all for the feedback. It does help to confirm, and get a few other perspectives.

Here's the pages ...

 

Many of us are on the low mileage track. I just suck it up and follow the maintenance schedule by the book.

 

That makes sense and for certain items you'll not expect there to be a warranty claim denied because of a lack of following the schedule. I mean, if you don't change your spark plugs at 60k, what warranty could be affected? If your car is having misire or decreased performance or fuel economy, it just makes sense to change the spark plugs if they are reasonably due, and that's something you always pay out of pocket for anyways.

For fluids, they all have really important functions to prevent friction, corrosion etc. and neglecting fluids can have much worse outcomes if you ignore time/mile intervals - motor oil, brake fluid, coolant, transmission and differentials.

For tire rotation, as long as the tread depth stays within Subaru's parameters, less than 2/32nds tread depth difference among all 4 tires, it shouldn't affect anything.

As confusing as the maintenance schedule may be, if Subaru were to expound on each maintenance item with it's own page, it could be even more daunting to the person who just wants to have their car serviced and maintained to keep their warranty intact. Sometimes thinking too much can make things worse than just blindly following a schedule.

 

The brake fluid cap is not 100% sealed - it lets air in as more brake fluid enters the caliper to compensate for pad wear. Even a can of brake fluid, once it's opened, cap screwed on again, is said to be discarded after 12 months. It's also said that brake lines and seams may be permeable enough for moisture to seep in. Water vapor can go through a barrier much more easily than brake fluid. I've never removed a brake fluid reservoir cap and had it act like it was under vacuum.

The brake fluid collects moisture much quicker in a humid region like Hawaii.

 

I don't intend to argue but I don't believe this is 100% correct. With all brake systems I've worked on the reservoir cap has a rubber bladder inside it and as fluid lowers in the reservoir, the rubber bladder, that is vented to the atmosphere, collapses into the space once held by the fluid. But air never touches the fluid. The systems are intended to be 100% sealed.

Brake fluid flushes are one of those "services" that, and this is my opinion only, are little more than money makers for the shops. I could type out a book based on my experiences working on brakes from a professional perspective over the last four decades but I'll spare readers the time. In the end I've come to believe brake flushes are unnecessary, especially at the intervals called for in most manuals and serve as nothing more than easy upsell money makers for service departments.

Yes, brake fluid is hydroscopic. Yes, brake fluid gets nasty over the years. But it's not the giant issue some make it out to be. Long before nasty brake fluid will present itself as a problem the vehicle will be on it's third owner or in a crusher.

 

I only drive about 2000 miles every 6 months and I do change my oil and filter - here's why on my car and maybe less of an issue for yours:

• The 2.4 turbo seems to cause oil to lose viscosity twice as fast as the naturally aspirated 2.5
• My engine is direct injection which generates soot in the oil, unlike your port injected 2.5
• I do a lot of short trip driving which causes fuel dilution of oil in a direct injection engine

So understanding the maintenance may not be a one size fits all, depending on the specifics of an engine, how it's driven, and what it does to the oil - the "severe service" notes come in to play here.

What's common to both our engines is:

• If you do short trip driving it can accumulate moisture in the oil that can acidify the oil - that's where the TBN in a used oil analysis provides some insight. EP formulas have more robust TBN additives and oxidation/sludge resistant base oils.
• Low tension piston rings and valve lift mechanisms that can get gummed up with sludge.

It's been long held that for street use, changing your oil frequently is more important than how fantastic your oil is. Nothing wrong with using M1 EP but I'd rather change my oil twice a year with cheap synthetic oil than hang on to premium oil for twice as long. Having said that, if you are extending oil change intervals, an EP formula is better than cheap oil but running it for 20k miles would be a huge mistake - I know you're not doing that.

Nobody's insisting that everyone follow the same schedule - but there are reasons why for many, frequent oil changes are best practice and the maintenance schedule is a reasonable guide. I doubt you'll run into problems given your engine and your choice of oil. Just saying that your best practice might not be best for someone else.

 

I’m pretty sure that both the 2.4 and 2.5 are direct injection?
Ok I see you must have been replying to the 2015 persons post -

 

Certainly, for oil changes, it's whichever comes first, but I can see the argument of miles for other things like spark plugs for example, or even brake fluid changes. My service department told me come in every 6 months and I bought the 3 year/36K maintenance plan. (BTW, it's really 4 year/36k as I was told if I don't reach 36K at 3 years, they extend it a year)

 

Brake fluid is hygroscopic. Which means that it pulls moisture from the air and can deteriorate just sitting there. Most people neglect it because their brakes "work", but the problem is that the brakes will continue to work until you need them most, when the water will turn to steam and suddenly the brakes don't work.

 

I have accelerated my oil change intervals to about every 3500-4000 miles. This ends up being one additional oil change per year, compared to the 6000 mile interval, since I drive a little over 1,000 miles per month. I suppose it's closer to 13,500 per year, so for me, it's more "miles" and not "time"

My reason for that is because I drive mostly highway but I do some suburban driving which pushes me into the severe category. In my opinion, with the turbo engine, I think it's too long to go 6000 miles and beat on that oil for so long. The mantra of "oil is cheap, engines are not" is echoing. Oil's characteristics do change over time, and I don't want to play around with anything that might accelerate direct injection buildup.

At the end of the day, for warranty claims, follow your book and do time or miles.

For practical reasons, I am doing oil changes 3500-4000, my differentials and PCV about every 30k miles, my engine air filter and cabin air filter yearly regardless of miles, and plan to do spark plugs at 60k per the book and will also change out the serpentine belt at the same time for preventative maintenance. Additionally, at 60k, I will ask that they do a CVTF change but in my previous Subaru CVT's this has been met with some resistance. I always replace my brake fluid every 2 years (this is usually close to 30k anyway) due to the ocean moisture. I will likely also ask for a coolant change at 60k or 75k also even though it can run longer. Again, the idea is preventative maintenance, and get the fluid out of there and replace with fresh fluid.

 

FWIW we just did the brake fluid at 90K miles, only $100 at our dealer; every 30K miles IIRC from Subaru's maintenance schedule. The brake response is noticeably better; we're still on the original pads and rotors all around.

 

PCV valve should be changed if you buy a used car, have oil consumption, or the car is say 5 years old. If you've been changing oil consistently every 6 months or 6000 miles whichever comes first, it should not clog in just a couple years. Note that MrSubaru isn't doing this on a nearly new engine - it's a 20 year old and crusty Gen2 (before 2005).

 

That was the video I was thinking of. For some reason I thought he recommended an actual interval of 30 or 36k but apparently not.

I assume that if one was doing UOA with every oil change that any problems with the PCV would show up there. Not sure what a PCV service would cost for those who don't want to do it themselves.

 

6months is BS. I would do 5-6K or 9-12months depending on your schedule and convenience.

 

its 6000/6 but after COVID started they did told deales to send people home if its under 3k miles.. or 12 month
and extend maintenance package from 24k/24m to 24K/48m (on 2019-2021cars ) new cars its back to 24k/24m

 

its 6000/6 but after COVID started they did told deales to send people home if its under 3k miles.. or 12 month
and extend maintenance package from 24k/24m to 24K/48m (on 2019-2021cars ) new cars its back to 24k/24m

Could you clarify what you mean by the part I bolded?

 

In Australia 15,000kms or 12 months (which ever comes first). 5 year unlimited km factory warranty. Time can be BS but if you want to maintain the warranty..............

 

Changing the oil is cheap insurance IMO. Although I drive enough that I usually don't have to worry about the time limits.

 

Yes it's not as bad in our cars - the Honda was much worse. I have not heard of any 2.4 turbos have their bearings damaged from fuel dilution or anything like that.

 

I almost always drive long enough for the engine to warm up so it's not something I've been particularly worried about on either vehicle. The CVT and diffs, on the other hand.

 

Mileage. For years most of my cars got 3000 or fewer miles. If I'm following some time based maintenance I'd be changing out nearly new parts or fluids. One of my cars was like less than 500miles/year, it could go years between oil changes.

Some stuff does wear by time, or rather, by environment - plastic components in the sun; tires from oxidation and gravity; battery from cold exposure. Spark plugs, by contrast, do not get old just sitting there, they're solid state electronics ie very carefully constructed rocks.

I have never ever changed brake fluid on a car, nor have I had any brake fluid ever pip even 1% on the brake fluid moisture tester. Your mileage may vary, I suppose. Buy one of those fluid testers on Amazon for 15$ and never let a shop bully you into changing it again until something has actually gone wrong.

 

I have never ever changed brake fluid on a car, nor have I had any brake fluid ever pip even 1% on the brake fluid moisture tester. Your mileage may vary, I suppose. Buy one of those fluid testers on Amazon for 15$ and never let a shop bully you into changing it again until something has actually gone wrong.

The problem with waiting until something goes wrong with your brake fluid to change it is that finding out that something has gone wrong often involves a serious accident.

 

Good points by all on my favorite subject; I've developed the minimum scheduled maintenance requirements for several new large transport category aircraft models as a maintenance program engineer. I have a draft calander based maintenance program for the Gen 6 that adds to Subaru's recomendations (I'm severe duty and low utilization). Industry standards are to publish the minimums, and it's okay to add tasks or reduce intervals based on utilization or service experience. I'm happy to see so many folks engaged on the subject.

 

Thanks. We use an industry standard Maintenance Steering Group revision 3 analysis to develop the initial minimum scheduled maintenance requirements. The analysis process isn't public, but you can read about executing the analysis process from the Federal Aviation Administration's perspective here:
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC 121-22C.pdf

While my team did the analysis, it's an integrated process with design engineering, operators, and regulators. Fuji Heavy Industries is a supplier on several of our projects.

 

I tried digging a little deeper and I kept seeing stuff about predictive maintenance in aviation that has developed in more recent years, so it's a very data driven approach both with and without sensor data, using various AI or machine learning algorithms including digital twins. I literally have a headache now. 🤯

 

I just went to the dealer for a 30K service on a '22 Outlback and wonder if I was suckered as it was a very hefty fee (and did not prepare myself by looking at the service manual). Long story short is that many of the items are listed as inspect in the manual but my dealer said I needed (on top of the oil change/tire rotation/air filters):

• Pcv valve service
• front and rear diff fluid change
• brake fluid flush and fill
• said I had carbon buildup and added a fuel system/throttle body service

Since I was a bit dumbfounded, I asked if this was required and they said yes so authorized the work. I bought the car new and has always been serviced by them with good work in the past. So maybe these were preventative work but the car had no symptoms to require such extensive work.
What are your thoughts? Time to bring my car elsewhere? Thanks for any advice.

 

I just went to the dealer for a 30K service on a '22 Outlback and wonder if I was suckered as it was a very hefty fee (and did not prepare myself by looking at the service manual). Long story short is that many of the items are listed as inspect in the manual but my dealer said I needed (on top of the oil change/tire rotation/air filters):

• Pcv valve service
• front and rear diff fluid change
• brake fluid flush and fill
• said I had carbon buildup and added a fuel system/throttle body service

Since I was a bit dumbfounded, I asked if this was required and they said yes so authorized the work. I bought the car new and has always been serviced by them with good work in the past. So maybe these were preventative work but the car had no symptoms to require such extensive work.
What are your thoughts? Time to bring my car elsewhere? Thanks for any advice.

I doubt you needed PCV valve service.
Front and rear diff fluid change would be called for if you tow stuff, but otherwise not necessary - not a bad idea to do it, but not "necessary" While some people have commented that their differential fluid didn't look great, I haven't heard of anyone having issues from not changing their differential fluid on a Gen 6.
Brake fluid flush and fill is usually due after 2 years.
The carbon buildup service was probably unnecessary unless you were having drivability issues.

The other issue is if they overcharged you for these unnecessary services.

Subaru of America cannot stop dealerships from recommending services beyond the maintenance schedule essentials, but maybe you could take issue with them calling it "required" but even then, unless it's in writing that the dealership said it was required, one may say that you misunderstood, or that they never said that. If it's not documented it didn't happen.

 

Following

 

The snippet I posed was from a Lexus - I know what you mean about the bladder/bellows thing but not all caps are the same it seems.

Do you live in a particularly arid area?

 

Arid? Central Indiana is more tropical in the summers, 90's and 90+ humidity. Winters are opposite, very, very dry, need a humidifier to breathe, dry.

 

I don't believe in the service time intervals. They were developed for conventional oil and even that was 3000 miles or 12months. Now that pretty much every car uses synthetic oil, there is no need for the 12month interval at all as the oil does not "breakdown" like conventional oil. 6,000 miles seems to be about 1/2 what it should be. I was getting 15k on my '17 turbo civic before change oil indicator came on. Also, my '15 Golf TDI (diesel) called for 10,000 mile oil changes and that was some dirty oil, but only 53% life used according to the sample sent in for analysis. That being said, I will perform the 6,000 mile oil changes, at least through the warranty, and follow all recommended service based on the milage service intervals. My opinion is time means nothing if the fluids are synthetic.

 

As previously noted, it's not just oil that has time limits. Do you use synthetic brake fluid?

 

Yes I was referring to a port injected 2.5 but even with the direct injection 2.5 it seems to not thin out the oil as fast as the 2.4 turbo does. I suspect that the 2.4 turbo, like many other small direct injection turbos, suffers from fuel dilution more than a naturally aspirated direct injection motor, plus potentially more shear from higher loads and the turbo. Turbo motors tend to run very rich under boost and that extra direct injected fuel can cling to cylinder walls and get washed into the crankcase, when the engine isn't fully warmed up, e.g. short trip driving especially in winter.

 

That's interesting, as fuel dilution was an issue with the 1.5L turbo in the CRV. Primarily those that drove short trips which didn't allow it to warm up and burn it out.