With a 2021 Subaru Crosstrek with the 2.5L engine/GDI.I do mostly highway driving and have been changing my oil every 6K/6 months.I see that many people with GFI engines do 5K.Would this be advisable in my situation?Thanks
2021 Subaru Crosstrek 2.5L; oil change interval 5K or 6K ?
- Thread starter Joeescape63
- Start date
Highway miles 6k works if synthetic oil
I would send a sample for an oil analysis. That will give you a baseline and an idea whether you need to change your oil change interval.
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+1 And may be a wise idea to look into the lab you choose to ensure they accurately measure fuel dilution. If UOA not for the OP I'd think it reasonable to stick to 5k OCI with a quality synthetic.
every 5k is easier to remember on an odometer?
dnewton3
Staff member
Rather than ask what others think, why don't you get a few UOAs and find out for yourself?
I'm not saying that to be sassy, but rather because your unique driving style and conditions may or may not make that extra 1k miles of value.
Asking others what they do isn't helpful until you understand if your particular car responds in a "normal" manner in terms of wear trends and rates.
Why guess when you can know? Get some UOAs.
I do lesser of 10k miles or 1-year.
Under warranty and without UOA, no way would I do this when the warranty and GDI steers you to sub-6k mileages.
Out of warranty and after 3-4 UOAs showed that the oil was still serviceable at 10k, I’d let it rip, and probably only do a UOA every 3-4 years.
As a matter of fact, since I had several UOAs in the bag in the 6-10k range on it, I’ve gone to at least a yearly schedule on the ‘18 Forester I service. From Christmas 2021-2022 it ran Amsoil SS 5w20 for 365 days and 10,010 miles (which performed great and didn’t use an ounce over that time), and is currently running PCMO 5w20 from the brand that when I type their name, one board member clutches his teddy bear tightly and shrieks furiously because of my enthusiasm. That oil has been in service since 12/27/22 and is at about 12k miles of daily use; I should be changing it in the next few months and will probably do a UOA since it’s been awhile.
WearCheck NC will most likely be where the sample goes, but Horizon/OAI is closer.
3k OCIs would be my choice with GDI. Maybe 5k if the oil doesn't drain jet black and reeks of gas.
As long as your engine is getting up to full temperature on most trips, 6k is fine. Fuel dilution stops increasing after the first 1k miles or so, so it's no reason to change the oil early. On GDI engines, there will be soot in the oil can increase timing chain wear, and the only way to remove it is with an oil change, but this isn't a problem area for Subarus.
If 6 months /6k miles oci working for you and your vehicle, stick with it. 5k oci won’t hurt either
5K is nice because it's easy to remember. You can just look at odometer. No need to put a sticker in the window or something. But if every 6 months on your car works out to 6k miles, that's totally fine too. I wouldn't lose any sleep over a 6-month interval that happens to be around 6K.
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Many companies including Toyota use 10K as the bench mark for warranty purposes. What is the benefit of changing oil sooner except being Old School.
I use my trip odometer for my 6000 mile oil changes. Most cars have 2 trips odometers now
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For a new age car and engine I’d do 4k oci
Imho it depends on the engine, my Sportage starts developing sludge after 4k miles so I keep OCIs at 4k miles. I know as I tried extending to 5k miles and drained oil was a bit chunky.
