Oil changes. Time vs km

[Seth1968]

For someone who drives very little, how relevant is the time factor? More specifically, does the oil begin to break down around that time factor? Moisture in the oil?

Also, let's say the manual states an oil change every 6 months or 10,000 km, but you only drive 10,000 km a year. Should one still change the oil at 6 months, or wait until the 10,000 km interval? Would it affect warranty if the latter?

[ExtraSlow]

Moisture in the oil can be a factor in vehicles driven infrequently, although less so if stored outdoors in Alberta because the humidity is so low.
I change once a year on most of my vehicles which works in my case for time and mileage.

[Seth1968]

Moisture in the oil can be a factor in vehicles driven infrequently, although less so if stored outdoors in Alberta because the humidity is so low.
I change once a year on most of my vehicles which works in my case for time and mileage.

How does the moisture get in the oil, and wouldn't it "burn off" at normal running temperature?

[bjstare]

Also interested. This is the first winter that I've stored one of my cars for the entire time (heated and humidity controlled garage). I've only driven maybe 3k since my last oil change, so I'm not thrilled on doing it again come spring if not necessary. 10L of synthetic ftl haha.

[killramos]

I don't know the material science of it, but if it says 6 months or 10,000 and you drive 10,000 a year that means you change at 6 months. It will affect your warranty, since changing once a year in that scenario would construe not following the maintenance schedule.

I usually time out my cars rather than mile them out for oil changes.

https://www.amsoil.com/newsstand/motor-oil/articles/why-motor-oil-deteriorates/

The oxidation and potential sludging are what I would be most concerned with.

[Sugarphreak]

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[killramos]

See I would rather swap in spring, and have fresh undegraded oil in the engine for when it is actually operating?

[revelations]

I only drive both of my cars 6 months of the year now, and they both live in a comfy heated underground lot. They both have high grade synthetic in them, and I am putting less than 3000km on each of them a year.

At this point I've started changing the oil in them only once a year, usually just before I stop using them for that year. That way fresh oil is in the engine during the 6 months of downtime, and it is ready to go when I re-insure them for DD use. I also try to idle them for about 15 minutes every 2 months when in storage just to circulate the oil a bit.
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Do not do this. Either drive it or store it.

Idling is bad for all vehicles and especially ones you've stored. All you're doing is contributing to a quicker break down of the oil.

If indoors, disconnect the battery (or trickle), add fuel stabilizer and leave it.

[Sugarphreak]

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[killramos]

Beats having degraded oil not protecting the engine when it's under stress.

New oil will help clean out any sludge buildup come spring. I have also done a pre-winter oil change after a hard use summer if i felt like it.

I think its a moot point for your's and my use scenarios ( which are the same ). You could probably eat off the inside of an engine that sees under 10,000km a year and gets its recommended annual synthetic change.

[Sugarphreak]

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[Thaco]

i only drive my truck for camping, less than 5k a year, i change the oil each year in the middle of the summer.... i've always ignored the "date" recommendations... i think its just a way for oil change places to scam people since i cant recall seeing a time lifespan for oil changes in any of my vehicles owners manuals. always just shows the KMs

[ShermanEF9]

oil gets more acidic overtime which can cause corrosion of internals. best practice is to change it every 6 months or so less.

[BokCh0y]

For my sons IS, since he doesn't drive it and we'll usually put maybe 2000 km's on it in a year, I change it out once a year. But makes sense the acidity, looks like It's getting a change once it gets warm.

[jacky4566]

A bit on the overkill side but here is a good run down as to how Oil Life Indicators work and the algorithms they use:
https://etda.libraries.psu.edu/files/final_submissions/392

You can see his approach to oil aging in section 2.3.5.

I used this paper to make a GM style oil life indicator for a Subaru. #Nerdlife

[Xtrema]

If it's a lease or under warranty vehicle, stick with the manual.

If it's an owned or out of warranty vehicle, an extra oil change ain't going to hit your pocket book that bad even if it sits just for peace of mind.

Unless someone has article against sitting with fresh oil and starting with fresh oil, fresh oil goes in before storage and replaced before bringing out of storage.

And for OP, if you want to do yearly oil change at 10k that's a DD, switch to synthetic (again assuming you have an out of warranty car).

[Seth1968]

If it's a lease or under warranty vehicle, stick with the manual.

If it's an owned or out of warranty vehicle, an extra oil change ain't going to hit you pocket book that bad even if it sits just for peace of mind.

That's what I'm going with.

Thank you all for the replies.

[Xtrema]

That is true, I could probably get away with changing my oil every 2 years and it would be just fine, haha

I doubt that there is any significant degradation of synthetic oil over even longer spans of time unless it is exposed to extreme heat.... mostly you change it just to keep it clean

And really, in Vancouver, you won't see many days under 0 and the roads are not pepper with salt/sand mix in winter. I'm sure you can get away with less frequent changes if you want.

[94boosted]

You'd rather have used & abused oil mixed with engine sludge sitting in the engine for 6 months?

If you change it going into storage, it isn't like the oil that hasn't been exposed to heat and wear would degrade by the spring, especially synthetic

:werd:

Everything I've read on storing vehicles says to change oil prior to storing. That's what I've done with mine for years.