Why Changing Your Oil In Your Subaru Every 3000 Miles Is A Must For Most Drivers

I often have conversations at the shop about oil changes.   There are a lot of different opinions and as a result a lot of confusion.   But the reality is that oil changes are a very necessary part of your Subaru’s  longevity or lack thereof if not done as often as needed or done with poor quality parts.

All car manufacturers have a normal and severe maintenance schedule, and if you’re driving habits fall into the manufactures definition of normal then maybe it makes sense to follow that schedule.  But if you use your Subaru or any other car you drive in any fashion other than starting it up getting on the freeway where you travel at freeway speeds until you reach your destination where you shut it off and then repeat this use in this fashion the majority of the time you drive it, than you do not fall into the normal maintenance schedule.   The real reason for the different maintenance schedule is to give the appearance of having lower ownership costs.

I have heard to many times that a customer thinks that changing the oil every 3000 miles is something a well known lube center dreamed up.   The marketing of the 3 month or 3000 mile oil change service was taken to new heights by the lube centers, but they sure didn’t dream up the idea.

When I started in auto shop we learned that the hardest thing an engine goes through is the heat of the summer and the cold of the winter.   You should start the summer season with fresh engine oil and once the summer is over you should change the contaminated oil out of the engine as the excessive heat can be detrimental to the effectiveness of the oil.  Conversely the engine should start the cold of winter with good fresh oil and sometimes a thinner grade of oil should be used to help the cold oil get to the top end of the engine quicker.   Once the winter season is over the sludge that once was oil should be drained out.   There you have it, the 4 oil changes a year your car should have.

I know there are companies out there telling you that if you use their synthetic oil you can forgo the 3000 mile thing.  I have heard customers and read forums on line talk about having an oil analysis done to prove the oil was still ok 5000, 7000 and even 10000 miles from new.   But is the oil filter still working?   Does oil that still has lubricating properties mean that it is ok?  While synthetic oil can stretch out the oil change interval the level of the oil should be monitored very closely regardless of the product used.  The other fluid levels in the car such as the coolant need to be topped off periodically as well and the tires inflated too.  If the service interval of the oil is stretched out the service of the rest of the car suffers as well.

How does the whole system work?   Oil lubricates and cools the engine; in fact the oil in your engine is about 1/3 of your engines cooling system.  As the valves open and close, the pistons move up and down it is oil that keeps the moving parts moving easier.   The engine is the hub of your car it all starts with the rotation of the engine, the easier the job the engine has of all of its parts moving freely the easier all of the parts the engine is in turn supposed to turn will move as well.   Yes slacking on oil changes poses ramifications to more than just the engine itself.

As the engine is injecting fuel into the cylinders to provide the explosion that powers the engine not all of the fuel is burnt, we do not achieve 100% combustion with the internal combustion engine.  The excess fuel slides past the piston rings and into the crankcase where it mixes with the engine oil.  Over time a lot of excess fuel can end up in the crankcase.   The fuel mixed with the oil can degrade the lubricating properties of the oil and lower the flash point of the oil as well.  Another words the longer the oil is in the engine, the more fuel it collects, and as this oil fuel mixture is used to lubricate the parts in the combustion chamber the more likely it is to burn away, out of the engine into the exhaust and out the tail pipe.  Over time the engine can burn a significant amount of engine oil.  Next fuel is a solvent that can and will eat away at seals and gaskets causing leaks that will need to be repaired.  Try pouring a thimble full of gasoline on asphalt and watch how easily the fuel eats away at the road.  Imagine what contaminated oil can do over time to the head gaskets in your Subaru.

There are systems in place designed to help remove the fuel from the engine oil, one is the positive crankcase ventilation system or PCV, the other is called the breather hose, or breather tube.  On a Subaru you will find a rubber hose attached to each valve cover gasket and then traveling up to the air intake tube.

Here is how the system should work, once the engine oil gets up to temperature the fuel vapor and contaminates can separate themselves from the engine and this vapor can be pulled back into the intake manifold and be re burnt or introduced back into the combustion chamber.   This helps clean up the engine oil and prolongs the oils life.

Here is the problem with this, if you get in your car and make short trips, or spend a lot of time “idle” in traffic this is never going to happen in your car.   And this is why maintaining your Subaru based on how YOU use it, is the only way to get as much value out of your car as possible.

Ask yourself if you think the car companies really want you to keep your car 10 years take care of it and have it last or buy another car every 4 years.

Next imagine that you own a factory with rows of equipment that all needs maintenance on a regular basis or the chance of the equipment failing and costing you money and down time will greatly increase.   Do you think most informed business owners will follow a strict schedule to maintain the equipment, thus keeping profits high and replacement costs down or rather roll the dice and stretch it out.    The similarities are there.

Except that we often get caught up in this crazy notion of blue book value dictating how much  money we should put into a car instead of looking at replacement costs or the total value of keeping what we already own in good shape so it will last, but that is another article to write at a later date.

Here are some pictures of a 1997 Subaru Outback 2.5l Engine with less than 100k on it that had engine oil leaks at every possible location.  The owner admit tingly changed the oil every 7500 and has no idea what kind of oil was used.  The sludge build up is not good at all.  Over ten years the $500.00 or so in savings by stretching out the oil changes has been more than made up in mechanical repairs.

More Subaru cylinder head sludge build up

More Subaru cylinder head sludge build up

Sludge build up in a Subaru engine

Sludge build up in a Subaru engine

Subaru 2.5l cam seal leak

Subaru 2.5l cam seal leak

Subaru cylinder head Subaru 2.5l sludge

Thanks for reading


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76 Responses to Why Changing Your Oil In Your Subaru Every 3000 Miles Is A Must For Most Drivers

  1. Scott November 12, 2008 at 10:07 pm #

    Wow Justin,

    That is great advice, keep up the good work.

    See you soon for an oil change too by the way


  2. name October 5, 2011 at 11:49 am #

    Changing the oil doesn’t prevent gasket leaks. Nor does it prevent electrical failures or problems with the fuel system, etc., etc. My 30+ years experience says getting a good car is a roll of the dice. I’ve bought second cars of the same model because the first car was great; only to have the second car be the worst car I’ve ever owned. Changing the oil more frequently than twice a year just wastes oil no matter how you drive.

    • Justin Stobb October 5, 2011 at 7:08 pm #

      I am sorry but your thinking about this in the wrong frame of mind. You also wont like my response to your post but its intended to educate not offend.

      You will notice the title is “Why Changing Your Oil In Your Subaru Every 3000 Miles Is A Must For Most Drivers”

      The logic behind comments like this is exactly why the Auto Repair industry is a multi billion dollar industry. You can literally clean an oil slick up with a small amount of fuel, but somehow the concept of this also happening in your engine is lost to any that didn’t actually attend some sort of formal training like a 2 year trade school.

      A contributing factor to gasket and seal failure on a Subaru due to the design of the H or boxer engine is contaminated fluids. A real lack of understanding about how well or rather how poorly the combustion chamber is sealed away from the crankcase and what happens when fuel is mixed with oil and the diluted oil is circulated around the engine is common place through out the industry.

      Poor some gas on a rubber seal or better yet dip a rubber seal in a container of oil and gas mixed and tell me what happens over time.

      Fuel is a solvent that deteriorates seals, corrosion from old coolant will cause gasket, seal and block damage.

      I truly attempt to educate about why oil is the cheapest insurance you will ever buy. Old oil affects seals and gaskets, friction thus engine wear, fuel economy and the performance of the entire drive train. It is one of the first things you learn if you receive formal education rather than just on the job experience.

      My industry is plagued with individuals that understand how to take it apart and put it back together but no real understanding about the separation of oil vapor form oil liquid at a specific temperature and how this really doesn’t occur for the majority of us stuck in the “Rat race” during our commute and as such oil needs to be checked and changed as needed based on how the vehicle is driven, some fall into every 3000 miles some every 7000 miles but assuming your the 7k type, or someone else reading a post does and having a engine fail or a gasket leak earlier than the guy who changes it every 3k is how your ownership costs go up. Its called counting your nickels only to have 50 dollar bills fly a way.

      The parts in a car are all made the same way, assembled mostly by machine and have exacting standards, the only variable is the use of the vehicle after purchase. There are some cars that have defective components but that is a whole different conversation.

      When I plead with Owners across the country to change their oil, check there oil and take responsibility for all of the aspects of car ownership its so there are no surprises, no major mechanical failures, no financial hardships.

      Planning on changing your oil twice a year and driving the vehicle in a way that dictates more maintenance than that is just a repair waiting to happen, either to you or worse the next owner.


  3. Tomasz Jarzecki January 28, 2012 at 1:37 am #

    Hi, Justin. Got an ’03 Outback with 106K. So far, so good. Love the car. I am the second owner and for the past 15,000 I have been running Mobil 1 synthetic with non OEM oil filters (Bosh, Mobil 1, Purolator) I live in Ohio and the oil change interval I set is 5000K. After reading your posts I am considering switching to 3000K oil changes. I am also thinking of switching back to conventional oil to offset some of the cost. I heard somewhere that once you go “synthetic” you should not go back to dino juice…. Thoughts???

    • Justin Stobb January 30, 2012 at 11:52 pm #

      We use 5w30 Synthetic blend oil for 90% of our customers and Full synthetic for the rest.

      Oil is one of those things that everyone has an opinion about, I like blend oil done every 3000 to 4000 miles. Followed by Synthetic and the same interval, the Subaru oil filter is just to small to let it stay on for much longer than that. Some people will just change the filter, but I am not a huge fan of that either. Its a piece of machinery and the less friction the rotating mass incurs the better off it will be, I use that one rule and that one rule only. Everything else gets clouded in the conversation about oil and intervals. There for example are many on the WRX forums who hate Mobil 1 and feel it caused rod bearing failure in their engine. I personally like Mobil one but not as much as I like Motul and Enos, which is why our shop stocks the later 2 choices. Does that mean Mobil one shouldn’t be used? This is what I mean by cloudy.



  4. Dechen July 2, 2012 at 11:09 pm #

    Hi I just bought a 1997 Outback and they have had synthetic blend oil in it. I am thinking of switching back to regular oil because it is cheaper. Is that ok for the car? Thanks.

    • Justin Stobb July 4, 2012 at 5:21 pm #

      Going from Blend to Dino is just fine.

  5. Dechen August 11, 2012 at 10:26 pm #

    Hi…what is the spark plug gap on a 1997 Legacy Outback 2.5L DOHC? Thanks

  6. Hans August 23, 2012 at 11:47 pm #

    Justin, great advice. I do about 4000 miles a year (retired) should I change the oil more frequently – every 6 mths – or is once a year enough? thanks

    • Justin Stobb August 28, 2012 at 7:59 pm #

      Hi Hans,

      You should change it twice a year at a minimum.



  7. Rahul September 28, 2012 at 1:54 pm #

    So much bad information and assumptions gathered together in a sigle page is really impressive. Having your oil analyzed is the only way to really know what is going on. When you get your oil analyzed they will included the amount of contamination including how much the gasoline has diluted and broken down the oil and particulates which would indicate weather or not your oil filter is still working. Every mechanic has opinions. 2 year trade schools do not make one a biochemical engineer no matter what your mechanic tells you. Change your oil and filter as often as makes you feel good. If you go longer than recommended get your oil analyzed. Opinions are like a__ holes, everone has one. You dont need to listen to mine either. :0)

    • Justin Stobb October 2, 2012 at 4:08 pm #

      “So much bad information and assumptions gathered together in a sigle page is really impressive”

      I sure hope you feel better after saying that?

      Do you really contend that spending $30.00 for an oil analysis, then spend money to change the oil is worthwhile? Do you understand the reasoning behind an analysis? Probably not, I will let you in on a secret.

      Oil Analysis, was a test intended to help fleet owners better know the condition of the internal components of the internal combustion engine, mainly large diesels and mostly to know when it was time to do a rebuild, so it could be planned for and downtime known about. But in a Capitalist Society like the great one we live in, you can’t stop there, you need to sell your idea to the world to expand the bank account, this is where the DIY crowd fits in.

      Should this be part of your maintenance plan? If you believe so by all means, but what would the average driver gain from this!

      Back in the “Ole Days” there were these guys called “carpetbaggers” that sold “snake oil” to folks of all sorts of intelligence levels, your rogue scholars all the way down to just plain stupid. It was never about the product, it was in fact one of the first examples of successful marketing of a products additional uses above and beyond its original intent.

      Next I find it incredibly rude, short sighted and ignorant that you would try to belittle someone who as at a minimum obtained some education in the chosen field they have pursued. I am not even talking about myself, but those in my industry that are constantly at odds with those that mock the profession as somehow lesser than their own.

      A life time as a “Biochemical Engineer” does not make you qualified to be an expert on the internal combustion engine, regardless of what the voices in your head may be telling you.

      Yes, I believe that someone who has studied and then mastered with experience the subject of Automotive Technology has an advantage over someone who studied say, Quantum Physics for 8 years when it comes to the true design and function of a dedicated system within an automobile. But you won’t find too many Automotive Technicians that think because they reflashed an ECM yesterday they are now masters of the universe, we’ll leave that up to the “Smart Folk”

      You may somehow believe your intellect superior, and you are most welcome to that opinion, what I try to point out is there is a reason to go to school, training or an apprenticeship program before becoming a Technician, I work in this industry I have seen good techs and bad, there has always been one constant, the ones that let in a little education around the factual aspects of the combustion engine, tend not to skip the most basic of details when suggesting maintenance.

      Its the ones that formed their own opinions based on “internet knowledge” often found on forums, typed in stupidity by the very “engineer types” that believe their singular wit superior to the rest of the human race, and seem to have an expert opinion on everything from Apples to Zebras.

      Lastly, checking and changing oil is as basic as it gets, I don’t believe in trying to over complicate it for the average family of four trying to get through today’s overworked, hussle and bustle by suggesting they send the oil out to be “anal” yzed.

      The round tire still rolls the best, checking your oil, adding when its low, and changing it when its due is still the best way to avoid engine failure, even if there are those that would like to reinvent the wheel.

      The point of the article is to help some Subaru owners avoid engine failure by not understanding what they own and how to maintain it based on their use.

      What I deal with on an almost daily basis is an owner that does not understand the very basics of car ownership either from lack of understanding or lack of desire to understand, the last thing I am going to do is over complicate it for them.


      • Asad October 25, 2016 at 3:42 pm #

        Hi Justin,
        I bought my first wrx 2016. I changed my first oil at 3000 second at 5700. its almost 9000 now. Should i change third one? I use amsoil oil ! what do you think of amsoil?

        • Justin Stobb October 26, 2016 at 8:30 am #

          Hello Asad,

          I would change the oil on a Turbo charged Subaru every 3 months or 3000 miles regardless of what oil you use.

          Hope that helps


  8. Dave November 24, 2012 at 7:28 pm #

    Hi Justin – I’m a big fan of your website and I’ve gained a lot of insight from reading your articles and posts. In fact, I bought a 2001 Subaru Impreza (EJ22) for my son and we found out later that one of the head gaskets was bad. We pulled the engine and did the work ourselves and it’s running fine now, I believe in large part to the information I gained from your website.

    I recently purchased a 2009 Impreza Outback Sport with 69K miles on it. I’m working out of state during the week and driving back on the weekends to see my family – it’s a 1000 mile round trip (all expressway), so I think it puts me into a “normal” maintenance schedule. I purchased Mobil 1 oil with the long life filter when I changed the oil last time with the idea that it would give me a 15,000 mile interval between changes.

    Based on what I’ve read in your article, it seems that maybe I’m expecting too much from my oil? Is my driving situation unique enough to consider the long life that is advertised for the full synthetic oil? Ultimately, I’m trying to do what’s best for the car – I take a lot of pride in maintaining my vehicles. I’d prefer not to have to change the oil every 3 weeks, but if that’s what is best, then I will.

    Keep the good information coming!

    • Justin Stobb November 27, 2012 at 2:01 am #

      Ho Dave,

      I think that based on the drive you are ok going out past the 3000 mile mark up to 5000 miles most likely, and perhaps even little higher. What I do want you to do is monitor Consumption after 2500 miles, and use that info as a tool as to when you should consider changing it.

      The more it burns, the more its diluted, the more its diluted the more its a solvent, the more its a solvent the more particles end up in the filter.

      Hope that helps.


  9. Desertboundwrx February 27, 2013 at 7:00 pm #

    Man why cant people just allow the wheel to be round! A bit late to point out but even with oil “analizing” it doesnt prove that the filter isnt going into bypass or will soon. March 1st is just around the corner so its a good time to start a 3 month oil routine. Ever thought about getting a shop down in San Diego?

    • Justin Stobb February 28, 2013 at 5:48 pm #

      Thanks for posting!

      There just isn’t enough of me to go around to ever consider expansion beyond one good shop.



    • Noah June 7, 2013 at 7:26 pm #

      Here Here. I live in Redding, CA and there is not a single independent Subaru specialty shop within driving distance, despite the streets crowded with them. I wrecked my Outback and couldn’t afford another one this go around, but I will have one again. Thanks for the good info Justin. Half of everything I learned what to do on a Subaru started by reading your blog and follwing your website.

  10. Nate July 18, 2013 at 9:54 pm #

    Hey Justin,
    Got my first subaru- a used 2005 outback 3R in January. Going for first oil change as i write this. I had been reading your articles for the past 6 months and everything you wrote had positively influenced my selecting and buying subaru and how i am going to keep it. Just wanted to say thanks for all the advice you put out there.
    Keep the good work going..
    How about opening shop in canada? Lots of Subarus out here I think..

    • Justin Stobb July 22, 2013 at 9:17 pm #

      Hello Nate,

      I love Canada, some of the most beautiful Country I have ever seen and as I am an Outdoor enthusiast so we would get along just fine. However it looks like opening a shop up there would have a lot of challenges from what I have heard from discussions with shop owners. We have had a few come down here from BC for larger repairs.

      Congrats on the Subaru I hope it gives you years of good service.


  11. Joel Young November 16, 2013 at 3:14 am #

    I think Justin is right. I have always changed my oil and filter at around 3,000 miles. My 1998 2.5L Outback has 216,000 miles on it and does not use oil between changes, and is driven about 60/40 city/highway. The only engine work I have ever done was installing All Wheel Drive’s updated head gaskets at 202,000. When I removed the heads there was virtually no sludge in them. I dropped the heads at the machine shop in the a.m. and gave them carte blanche to do whatever was needed, and returned home from work in the p.m. to a phone message saying to come get them. The machinist said they needed zero work on the valves, guides, and cam journals. I had them lightly surfaced and put them back on.

  12. yemaya December 23, 2013 at 10:20 pm #

    hi, I was going to change ignition wires and plugs when I discovered oil filled the plug cavities when I pulled off the old wires… Would this be a gasket issue? Like remove the valve cover, replace the top gasket, plus round gaskets down some rod by the plugs? Guy at a parts store said there’s a kit… that may remedy the oil leaking. Would appreciate your input. 2000 Subaru Outback with about 150K miles. Runs good.

  13. Scott McFadden February 20, 2014 at 8:58 pm #

    Hi Justin,
    Thanks for post. I wish I lived closer to your shop but, alas, I live in Portland.

    I have a 2005 STI with 160k miles and am experiencing some oil consumption. I change my oil every 3400 miles.

    I know that my driver side exhaust cam seal is leaking from inspection. Before I change this seal which doesn’t seem to be coating my timing belt, I thought it might be a good idea to inspect and change the PCV and hoses. In your experience, does this seem like a correct approach to you? Have you had this issue before with PCVs on this motor? As far as I know, the PCV has never been changed. Everything else has been maintained to Subaru’s recommendations (t-belt, water pump, and idlers) Is there anything else you could recommend checking to see if I am not dealing with a bad seal but an over pressurized crankcase due to bad ventilation?


    • Justin Stobb February 24, 2014 at 8:44 pm #

      Hi Scott,

      Id start with an inspection of the PCV and replace components as needed, Oil consumption on your model could be the turbo so I would have a look at that as well. Unless the cam seal leak is large I might hold off until I had a handle on the Consumption, as if you replace the seal only to figure out the oil rings are worn it was a lot of work for not.


  14. Ashley August 15, 2014 at 5:05 pm #

    Hi Justin!
    I am so thankful for this post! We just bought a 2014 Subaru Impreza. We are new to the Subaru world! For a 2014, would you recommend oil changes at 3,000 miles (with it being a new model)? We live in AZ, and drive the vehicle about 10 miles/day. Do you have any recommendations about this vehicle/maintenance?

    Thank you for your posts! They are awesome!

    • Justin Stobb August 18, 2014 at 9:31 pm #

      Hello Ashley,

      Thanks for the post, you may be okay at a 5,000 interval with the 2014. I would check the oil every few fill ups and monitor oil use and the condition of the oil based on how you are using it. During the summer months it may use a little more oil due to the heat and the Ac use.

      Hope that helps


  15. dave May 10, 2015 at 8:05 am #

    Hi Justin.
    I enjoy reading your articles and it sounds, that you really know Subaru’s inside and out.
    I would like to ask you a question about high mileage oils.
    I just bought a 03 Forester with 120 000 miles on the clock.
    Considering the Subaru head gasket issues, would it be a good idea to use high mile oil, since most of the brands say that their product will “condition and swell the old dried up seals”?
    On paper it sounds like a good idea, but I would really like to know your opinion on this.
    Also, would you be able to recommend a good brand along with the preferred viscosity number?
    Thank you in advance for any input.

    • Justin Stobb May 11, 2015 at 3:12 pm #

      Hi Dave,

      The preferred oil for that model is 5w30 Castol Synthetic blend, also called high mileage or GTX.

      Should be in the green Bottle.


      • dave May 11, 2015 at 3:59 pm #

        Thank you Justin.
        Being that the summers are usually pretty hot where I live (Southwestern Ontario), do you think it might be a good idea to run the 5W-30 in the winter only and switch to 10W-30 in the summer?
        My concern is, that the oil might get too thin and runny with the heat, thus inviting leaks out of places, that normally wouldn’t…..or would you recommend the 5W-30 all year round, regardless of the climat conditions?

        Also, would you be able to give me your personal opinion on Lucas heavy duty oil stabilizer?
        That one claims to be compatible with any oil and also claims to be able to form some sort of a protective barrier, which is supposed to be superior to the one that the engine oil makes….
        Thanx again

        • Justin Stobb May 19, 2015 at 11:18 am #

          Hi Dave,

          I am not sure which era Subaru you have so I cant 100% answer the oil question.

          As far as the oil additive, I don’t really have an strong opinion. I personally don’t really use anything, but its kind of a each to their own kind of a thing.


  16. Charles von Radesky May 16, 2015 at 4:08 pm #

    Very informative. From my experience with marine machinery, I have learned that lubricating oil does not wear out, but it does get contaminated. To eliminate problems caused by con-
    terminated oil, it needs to be cleaned continuously. Ideally, oil filters for Subaru engines would be much larger than what comes with the car. The only alternative is more frequent oil+filter changes. My 2007 Legacy GT Limited wagon came with 10W-30 Castrol GTX in the sump, which I have continued to use. Even though the Owner’s Manual says otherwise, I continue to wonder about using synthetic/synthetic-blend oil. At 90,000 miles, I do not have any leaks, and as far as I can determine “0” oil use between 3,000 mile-interval oil+filter changes. Can you suggest an oil filter larger than the OEM? Would there be any advantages to changing type and weight of lube oil at this point?

    • Justin Stobb May 19, 2015 at 11:12 am #

      There really isn’t room for a larger oil filter based on the location of the exhaust.


  17. bobboli May 18, 2015 at 5:58 pm #

    Hi Justin,

    After about a year or researching Forester models, I finally got a nice little 2005 XS with 62K miles from the original owner. I took it to an independent Subaru mechanic for the 60K service (incl. oil and coolant change), and when I asked what kind of oil he said 5w30, but emphatically added it should be *non-synthetic.” Is this simply because of the relatively low mileage or because that’s what they’d just put in it? Also, what kind of coolant should be used on this car?

    • Justin Stobb May 19, 2015 at 11:07 am #

      The car does not require Synthetic, if you want to spend the extra money on it that’s really up to you, but it wont really change the oil change interval.


  18. Mike P. July 26, 2015 at 7:27 am #

    Hi Justin,

    Really appreciate all your expertise on subarus and sharing your knowledge.

    I just had timing belt and components, mls head gasket, valve cover gaskets replaced on my 2007 subaru impreza 2.5i with 166 000 km. I have been using Amsoil filters and Amsoil sythetics (5W30 and eventally 5W40 Euro) and most recently Shell Rotella T6; not much difference in terms of oil consumption. I have been adding anywhere from 0.5-1 quart per every 1000km on 10000 km oil change intervals with “supported evidence from oil anaylysis”

    After reading your article, I realize that switching to GTX may be the best option with more frequent oil and filter changes; every 5000km? I do mostly 80% highway and average 20 000 km/annually.

    I was encouraged and have read that an oil change after such major work, as mentioned, should be done within the first 100km after, but my mechanic suggested after about a week or none at all – request some suggestions. Also, would it also be fine to go from synthetic to the GTX (i belieive it is a semi synthetic high mileage)?



    • Justin Stobb July 28, 2015 at 12:18 pm #

      Hello Mike,

      For your car we would suggest Castrol GTX, or high mileage. Either one will be a semi synthetic or “blend” type oil. I would use 5w30 and really consider oil changes every 3000 to 4000 miles depending on how you drive it.


      • Mike P. July 29, 2015 at 3:45 am #

        Thanks for the reply, Justin.

        Is it necessary to have an imminent oil change after having head gasket replaced and machined?

        • Justin Stobb July 29, 2015 at 11:59 am #

          I would check the oil after 500 miles, again at 1000 then every 1000 miles (provided its not using oil) and change it at the 3000 mile mark.


  19. Linda August 11, 2015 at 3:46 am #

    I have a 2014 Impreza and my CHECK ENGINE light has been coming on and off for the last 6 weeks. My local dealer couldn’t find the problem but suggested an oil change. When the light continued to come on and off after the oil change he suggested cleaning the valves. I went to another Subaru mechanic this week and he checked the valves – they were clean – but the light was still on. Subaru told him to chang one valve and when the CHECK ENGINE light continued to come on he changed a second valve. My question is when my car was hooked up to the computer in the very first place why wasn’t more accurate information transmitted? Why was it a trial and error situation on the part of both mechanics? And is it likely that the CHECK ENGINE light will go on again or does it sound as if the problem is now permanently fixed? Many thanks

    • Justin Stobb August 18, 2015 at 1:31 pm #

      Hi Linda,

      Whats the code they are telling you is setting?

      the 2014 is under warranty, if you have trouble getting a real answer from your dealer call 1800 Subaru 3


  20. Gary R August 27, 2015 at 11:45 am #

    100% agree with this article. I bought a 2000 Subaru Outback brand new and changed the oil every 3000 miles like clock work. I was NOT brand specific on the oil but did keep it changed. That car ran for 306,000 miles. One time both head gaskets were replaced, normal tune ups and the normal T-Belt changes were the only time the engine was touched. The original trans lasted that long as well. The car would have gone longer had the T-Belt not broke. 3000 Mile oil changes are the way to go.

    • Justin Stobb August 27, 2015 at 12:41 pm #

      Well said, thanks!


  21. vickey September 2, 2015 at 10:25 pm #

    I appreciate your website Justin. I came here because I am confused about what kind of oil to put in my 08 Forester that I bought at 13,000 miles. It has 46,000 miles on it now. The manual states to use 30W oil, which I recently heard isn’t made anymore. I think it has been running with 5-30W instead. Then I went to a new mechanic who talked me into synthetic. But I noticed on the synthetic, smoke would sometimes come out of the exhaust pipe, which concerned me. Then one day, before the 3000 miles were up, I checked the oil level gauge, and the level was so low I panicked. I added oil but had never had this happen with regular oil. So I went to a different shop and back to regular oil. The Forester seemed fine. Now I’m taking it in for spark plugs, etc to that mechanic who is pressuring me to go back to synthetic again. He says its better for the engine. But I’ve been reading a lot and it sounds like synthetic oil and Subaru seals may not be compatible, which could be why it smoked while running on synthetic? But then I wondered, was the synthetic cleaning out the “sludge” I’ve read about? This mechanic told me if it smokes with synthetic the car could have head gasket leaks and to use Blue Devil Seal Softener. The engine only has 46,000 miles on it and I’ve taken care of it that I don’t want to consider it has a problem like that already. It doesn’t burn oil with regular oil, only with synthetic. He told me that would clear up after a couple oil changes. Umm I don’t know what to do. What would you do? thanks so much for any advice to un-confuse me.

    • Justin Stobb September 15, 2015 at 9:20 am #

      Hi Vickey,

      Fire the “mechanic” who told you to use any blue devil product. Look for a Technician instead.

      The car requires 5W30 oil, and synthetic really shouldn’t be used.

      Stick with basic oil, or blend. I suggest 5W30 Castrol GTX or high mileage.

      Synthetic oil isn’t a detergent oil so its not going to clean anything, it burns away quicker most likely as a result of the additive package in the type of oil being used.


  22. Paul October 14, 2015 at 10:43 pm #

    Hi Justin,
    I have a Legacy 2008 wagon. A mechanic put Total Rubia TIR 7400 15W40 which is a heavy duty synthetic oil for diesel engines. My car has a petrol engine. Is this ok or I should be worried?

    • Justin Stobb October 15, 2015 at 7:20 pm #

      Hello Paul,

      I would ask your guy to drain it out, replace the filter and put 5w30 back in, I am not sure where you live but if it gets cold there before it’s taken care of engine damage could occur. Also the Variable valve train wasn’t designed for that grade of oil and you may start setting check engine lights.

      Hope that helps


  23. joe October 25, 2015 at 9:10 am #

    Hi Mr. Stobb
    I purchased new a 2011 Forester. I live up in Toronto Canada. Since the purchase I’ve put on about 32000km, maybe 20000 miles. I drive like an old lady, speed limit, no hard braking, maybe drive the highways 5 times a year to go to a beach somewhere. I have been following the Subaru maintenance schedule to a tee but for someone who only drives the car once, twice a week for maybe 20 miles round trip is it a good idea to change the oil every 6 months? Do you recommend sticking with the dealership or would you think going to auto center which is much cheaper a better idea?
    My second question, sorry, if you don’t mind, is how long should brake pads last? The rear brake pads where replaced last Spring with only 30000 km use. And now they are informing me that my tires are worn out and should be replaced after 4 years. The thing is I have winter tires with steel rims put on in October and removed in March so the regular All Seasons that came with the car are in storage six months out of the year. Is this normal?
    I ask because I drove a 67 Pontiac Laurentian until 2011, rear snows put on in the winter, oil change once a year, replaced the pads around 1995. Just a silly comparison. Any answer to the above questions is greatly appreciated, thanks.

    • Justin Stobb October 27, 2015 at 7:19 am #

      Hello Joe,

      So I just cant state enough that I don’t like the idea of the Subaru Dealer for service, all they see is $ when they look at you.

      I cant really fathom a scenario where the rear brakes are worn out before the fronts, and before 60k.

      As far as the tires, I don’t know which ones they are and its possible they could be worn if they were not rotated properly, you haven’t mentioned if they were rotated at least twice a year..

      As far as how often on the oil changes?

      It’s not a waste of money to change the oil 4 times a year, but I can see with limited use why thats tough to follow. The problem is that sitting is tough on a car, tire rot, internal parts of the engine loose lubrication as the oil drains away from sitting, I can go on. Think of it like this, the longer you sit the harder it is to get going and if you were to go from sitting for hours to immediately running you might have an injury. While a car is a piece of equipment, the same basic principles apply, the longer it sits, the tougher it is on it to get going.

      Lastly, yes please look for a good independent shop, not to save money but to get better service.


  24. Mark November 11, 2015 at 8:56 pm #

    Hi Justin,

    I recently purchased a 2005 Outback XT Limited 5MT. I really like the space of the outback combined with a turbo for mountain driving. I’m just making the switch to full synthetic from conventional oil. I’m on a 3000 mile interval between oil changes.

    My question is about which oil to use. I really like Mobil 1 so I’m planning to use it but the outback just recently turned over 75,000 miles which is the point that Mobil 1 high mileage is recommended. The other reason I’m thinking of using high mileage is to combat a very small oil leak. Am I losing any protection/Etc by using the high mileage right at 75,000? For more background I’m also using OEM oil filters.

    Thanks in advance for your reply. Also, thanks for writing these articles/white papers, they are very informative and interesting. I actually had the banjo bolt replaced when I purchased the outback (63,000 miles) because of your article.

    • Justin Stobb November 12, 2015 at 12:22 pm #

      Hey Mark,

      Thanks for the Feedback.

      So at the shop we use a high mileage oil for anything not requiring full synthetic, high mileage oil can vary by the maker but is generally going to be a blend of conventional and synthetic. I see no reason why you should not use it.

      Hope that helps and good job on the maintenance!


  25. Sebastian Arcila August 24, 2016 at 3:47 pm #

    Hey Justin, just a quick question. I have a 95 impreza (gc8) 2 door 2.2l.(ej22) its leaking from the infamous rear main seal. I dont really have money or time right now to repair it the right way. Whats you take on “Bars Rear main stop leak” additive. According to the reaserch ive done people swear by that stuff and seams to work for what i need it to do. The car is my daily/rallyx project. I just need the leak to slow down or stop long enough to replace the engine and tranny in the future.


    • Justin Stobb August 24, 2016 at 4:01 pm #

      I am sorry but there is just nothing in a bottle that you should ever put in.

      You will over time cost your self way more then you will.


  26. Watson Chanaka September 11, 2016 at 2:52 am #

    Hello Justin, thanks for the great support you give us. Keep it up.
    l have 2 questions. 1. l am running a Subaru Legacy B4 2004 model, 2.0 GT. what kind of oil should l use for my car. l drive for short distances every day home to work and back about 14km a day.
    2. About 8km l do every day, its a dust road, it raises a lot of dust and during rainy season , a lot of mud. is that safe for my car. what other components should l change Regularly? l appreciate your help

    • Justin Stobb September 12, 2016 at 12:39 pm #

      Hello Watson,

      I would use 5w30 Synthetic blend. As far as what else, based on what you have said I would keep a careful eye on the air filter, and cleaning the Mass Air Alow Sensor with an approved cleaner is also probably wise.

      With the Mud Id try and wash it out of the undercarriage and wheels as it can collect in the wheel wells, wheels, brakes etc and cause problems.

      Hope that helps and I wish your car was available here in the US:)


  27. Watson September 13, 2016 at 1:39 am #

    Thanks a lot Mr Justin, l will try to work on your recommendations. Unfortunately l am in Mozambique and the state of our roads is very bad, Just bought the wrong car. Thanks a lot once again

  28. Ray September 20, 2016 at 6:16 am #

    Hi Justin, Enjoying reading your information. I have a 2008 impreza 5MT which was completely rebuilt. Unfortunately, it seems to be smoking on startup. I am using 5w30 full synthetic and 3000mile changes but I seem to need to add 1 quart per 500miles, any suggestions on how to proceed. I have advised my mechanic but I am unsure what the best next step is.

    • Justin Stobb September 20, 2016 at 9:40 am #

      Hello Ray,

      Smoking on start up is most likely worn valve guides and or seals, there are other possibilities, but that’s the typical kind of a thing, which is unfortunate if it was just rebuilt? There really is no testing that can be done short of removing the heads and having a qualified machinist have a look.

      Hope that helps and sorry about the news


  29. Watson September 22, 2016 at 6:13 am #

    Hie Justin
    Once again. i cant find oil for my Subaru Legacy B4 2004 Model GT 2.0. you advised me to look for 5w 30 Synthetic blend, but l cant find it. Instead l can find 5w 40. can it be a substitute, or what can be a substitute.
    The second question is, can you help me with the reference of rear wheel bearings, they are making noise as the car gains speed also the left wheel is kind of binding and heating a lot, just for a small distance. thanks a lot for the support

    • Justin Stobb September 23, 2016 at 11:48 am #

      Hello Watson,

      Not really understanding your climate makes it a little tough to answer the oil question but I think you should be okay.

      As far as the Wheel bearing and referencing the part number is what I think you are after, try this link


  30. Chris JM October 7, 2016 at 11:24 pm #

    Agree fully with the 5000 km interval. Buddy of mine who is somewhat of a Subaru guru did head gaskets on my 2004 at 200,000 km and made me promise to change oil every 5000 km. He currently has a 2007 Impreza in his shop for a head gasket job with only 100,000 km on it. He loves the cars.
    I do the same interval change on my old type 1 Beetle which was always the recommended interval. Cheap insurance at $30
    Chris JM

  31. Ken November 21, 2016 at 2:36 pm #

    Hi Justin,

    I have a 2009 Forester 2.5X Premium. I am planning to put Havoline 5w30 conventional oil. What are your thoughts about it? I have 150K miles as we speak…Do you recommend conventional or full synthetic since I have high miles? OR does it matter at all? I live in the midwest (Oklahoma).

    Another question I would like to ask is the coolant. It comes with Subaru long life 10 year or 100K…Do you recommend changing the coolant since I have crossed 100K or wait till 2019 to change it?

    Thank you for your time!

    • Justin Stobb November 21, 2016 at 3:17 pm #

      Hi Ken,

      I like 5w30 Synthetic Blend Castrol for that application. But Havoline Conventional should be okay as well, just don’t try and go 7000 miles, it wont work long term.

      The coolant should be tested every year after 3 years for the proper PH levels and changed when out of range. But if the car has over 100k it should have been done, its whichever occurs first 10 years 100k.

      Hope that helps


  32. Ken November 22, 2016 at 4:09 pm #

    Thanks Justin! Appreciate your thoughts!

    I have one more question….I noticed oil drips on the floor this morning…I am yet to take it to the shop for a diagnosis. In the meantime, a quick search online about the leak led me to this
    Here they say all Foresters up to 2009 model will need a head gasket replacement at about 80-120K due to faulty head gasket made by Subaru. I was wondering if you had similar thoughts or different and if you could please share them…

    Thanks again for your time! I truly appreciate your feedback!

  33. Chris Werner February 17, 2017 at 9:51 am #

    Please post pics of the same style engine with oil changed per your recommendations, for objective comparison of sludge etc.

    • Justin Stobb February 23, 2017 at 10:43 am #

      Hi Chris,

      There should be no build up, I have posted plenty of pictures on this site, Facebook, Twitter Instagram etc.

      But I will try to post a picture of a 1st gen 2.5l when I have one apart next.


  34. Paul March 1, 2017 at 12:06 pm #

    Hi Justin,

    I just bought a 2017 Subaru Legacy (2.5 Liter model). I spoke to mechanics at 2 Subaru dealerships and they tell me the synthetic 0W-30 should be changed every 6000 miles. I just use my car to drive to and from work every day, nothing crazy.

    What are your thoughts on this? This goes against everything I have ever been taught. I’ve always been told every 3000 miles. Don’t get me wrong, the synthetic oil changes are MUCH more expensive, so I like the thought of the savings but not at the cost of my engine.

    Any advice you can offer would be appreciated.



    • Justin Stobb March 1, 2017 at 4:40 pm #

      Hello Paul,

      I would change the oil the first time at 3000 miles or sooner as its really brake in oil.

      Form there I would start checking it for level and condition at around the 2000 mile mark from last oil change, well actually I want you to check the oil level more often then that but for the purpose of trying to tell when its due I want you to start at the 2000 mile mark from last service and really pay attention to it every 500 miles. As soon as its really dark, smelly or 1/2 quart low that is the car telling you it should probably be changed.

      This is changing the oil based on how you actually use the car and not a everyone fits into this mold kind of a thing.

      Hope that helps


  35. Nick March 5, 2017 at 4:42 pm #

    Hi Justin,

    I just purchased a 2017 Subaru Impreza 2.0 Base model. The owners manual says to change the 0-w20 Full Synthetic oil every 6,000 miles and no early first oil change. The dealer said to change the oil at 3,000 for the first and then every 6,000. Just wanted your thoughts… I live in the U.P. of Michigan and drive mostly city with a max speed of 60mph on the “highway”. I was also planing on doing all my own oil changes with a Genuine Subaru oil filter and whatever the cheapest full synthetic oil is. Also, what do you think about the “FUMOTO” oil drain valve? Thanks! This is my first Subaru and so far I love it!

    • Justin Stobb March 8, 2017 at 1:06 pm #

      Hi Nick,

      So right off the bat I am not a big fan of drain valves, they scare me and I have seen more than a few fail.

      I like the idea of the first oil change at 3000 miles, and from there id say 6000 might be okay but you want to check it lots and often after 3000 miles if not sooner just to check level and condition as you are learning your car and if how you use it means 6000 miles is going to be okay.

      Hope that helps


  36. Joe March 22, 2017 at 6:58 pm #

    Justin, I am in New Brunswick Canada and this last November I had the first oil change on my 2016 Crosstrek expecting dealer would use Mobil 1 as was done on my previous Subaru Legacy. However, they used a bulk oil and my invoice indicated it to be Mobil Super Synthetic 5000- the dealer indicated there was no difference from Mobile 1 but I am not buying it. I am shortly going to have the 1st change on my 2017 Legacy and am wondering whether to insist on using Mobil 1- am I am being too fussy or is the Mobile Super fine? I drive between 6,000 miles and 10,000 miles and change my oil 3 times a year including after the winter season regardless of the milage. If I go with Mobil 1 should I go with the Extended Performance or Advanced Fuel Economy. Thanks.


    • Justin Stobb April 4, 2017 at 12:36 pm #

      Hi Joe,

      Subaru of America requires cars use Indemitsu 0w20 for your Model, no idea what Subaru of Canada is up to there.


  37. Marino Bartolomeo April 3, 2017 at 3:47 pm #


    I use oil Motul v3000 is the best and full syntetic every 5000km ( Italy ) in my WRX 2004, when the car haved 70000km i put 100 gr bisolfiro molibdeno ( is a lubrification dry aircraft engines ) and my friend certified my engine work fine to 300000Km, now have 96000Km. After many year one engine make minor Km, example engine 20 year make max 25000Km but same engine in 5 year possible make 500000km, becouse ??? after many year the properties metals costruction in the engine collapse.

    Many thanks


    • Justin Stobb April 4, 2017 at 12:31 pm #

      Hello Marino,

      I visited Italy last Summer with my family, it was amazing!

      Thanks for the Post