Auto Maintenance Question

[BrooklineBiker]

I own a 2021 Toyota Corolla purchased used.

The car had its oil changed with synthetic oil when purchased in Dec. 2022.

I've put 2408 miles on the vehicle since purchase. The car is usually driven weekly for short hops.

The mileage accrued to date is below the mileage justifying a change. However, the oil has been sitting in the car for nearly a year.

Do I need to change the oil now?

If not now, when should I change it?

[reeshau]

Yes, you should change every 12 months, regardless of mileage.

https://www.aaa.com/autorepair/articles/how-often-should-you-change-engine-oil

[Tester]

Change it now. A change of oil is too cheap to not do it yearly, especially since it is recommended by the manufacturer too.
Look in the car maintenance schedule and do what it says there.
For oil changes I am sure you will see both a mileage interval and a time interval, you have to use whichever happens first.

[HipGnosis]

I will be the voice of contradiction.
Motor oil does NOT age like food.    It doesn't evaporate and get thicker.
Some reputable sources say it's OK for '5 years' (under 'normal' circumstances).  I've read 10 yrs for synthetic.
Your short trips are 'harder' on the oil than the time it sits in the engine.
You are a prime candidate for synthetic-blend oil.
Please avoid 10 minute oil changes.
My grandfather owned a service garage that worked on cars and farm machinery.  My dad was an auto mechanic.  I've been a 'gear-head' my whole life.  Cars, trucks, and motorcycles.

[sonofsven]

I agree with HipGnosis, oil doesn't break down just from time, but from contaminates and heat.

[reeshau]

It's true there isn't necessarily a physical reason for a time-based oil change.  However, if you have a car under warranty, understand that manufacturers typically recommend every 12 months, and include verbiage like this one for the 2023 Chevy Silverado manual: (bolding is mine)

"Damage Due to Insufficient or Improper Maintenance Damage caused by failure to follow the recommended maintenance schedule intervals and/or failure to use or maintain proper fluids, or maintain fluids between recommended maintenance intervals, fuel, lubricants, or refrigerants recommended in the owner manual is not covered."

Powertrain warranties are frequently 10 years, so this even covers some Mustachian owners. :)

[SmashYourSmartPhone]

Do I need to change the oil now?

Yes, mostly because of the short hops.  That doesn't allow the oil to come up to temperature and boil off moisture, so it builds up more acidic products and such.

Also, new car, come on.  Don't cheap out on oil changes.  And don't cheap out on filters either.  Wix or NAPA Gold (same thing).  And never, ever ever ever put Fram on a car you care about.  Their cardboard is known to come apart and destroy engines more than it should happen (which is "never").

Motor oil does NOT age like food.    It doesn't evaporate and get thicker.

No, but the additive and buffer packages wear out, and it can build up corrosive byproducts after that.

If you want to play the long oil change interval game, it's fine, but please send regular samples to Blackstone Labs (https://www.blackstone-labs.com/) to find out what's actually in your oil and when you should change it.  Personally, I feel that's worth it for long distance high mileage vehicles, but if you're doing 2k miles a year, just change it with some decent oil annually and call it good.

Please avoid 10 minute oil changes.

Indeed.  I don't understand how they're still in business, any of them, with how much awful crap I see on cars that have been to those places.  Leaving the airbox open (or just snapping off bolt after bolt for it) is quite common, they'll drain the transmission and overfill the engine, the list goes on.  Get the equipment to do it yourself, and save the money and your car in the process.

[BrooklineBiker]

It's true there isn't necessarily a physical reason for a time-based oil change.  However, if you have a car under warranty, understand that manufacturers typically recommend every 12 months, and include verbiage like this one for the 2023 Chevy Silverado manual: (bolding is mine)

"Damage Due to Insufficient or Improper Maintenance Damage caused by failure to follow the recommended maintenance schedule intervals and/or failure to use or maintain proper fluids, or maintain fluids between recommended maintenance intervals, fuel, lubricants, or refrigerants recommended in the owner manual is not covered."

Yikes! I don't want to void a warranty.

Powertrain warranties are frequently 10 years, so this even covers some Mustachian owners. :)

[Tester]

I will be the voice of contradiction.
Motor oil does NOT age like food.    It doesn't evaporate and get thicker.
Some reputable sources say it's OK for '5 years' (under 'normal' circumstances).  I've read 10 yrs for synthetic.
Your short trips are 'harder' on the oil than the time it sits in the engine.
You are a prime candidate for synthetic-blend oil.
Please avoid 10 minute oil changes.
My grandfather owned a service garage that worked on cars and farm machinery.  My dad was an auto mechanic.  I've been a 'gear-head' my whole life.  Cars, trucks, and motorcycles.

His car is a 2021. Let's say something happens and he wants to use the warranty.
He can't go and yell them about reputable sources, they will say not my problem.
How much can it cost to get an oil change once per year? Even at the dealership it is cheap. I would only do it at a good service/dealer especially for the case I need the proof.

It is not a Lamborghini, it is a Toyota Corolla so an oil change  should not break the bank

More, even if it is not necessary to change the oil every year, does it make it worse if you change it?

[curious_george]

I would change it but not for any of the reasons listed here.

I would change it because it literally isn't worth thinking or worrying about at all. Oil changes don't cost much relative to the price of a new engine. If not changing the oil in over a year causes you to worry about if you made the right decision or not then you should change it.

I change my oil once a year. Full synthetic oil, Similar low mileage vehicles. But when I change the oil I give the old oil to my brother, who runs the oil for another year and 20k miles. He has been using my old oil for over ten years now, with no apparent negative effects outside of saving more money.

[cincystache]

The manual likely calls for 5,000 miles OR 6 months. I would change it once per year. Twice per year if you want to run this car for 20 years.

[Dave1442397]

I change mine every year, and I've only put 4500 miles on the car in the past three years.

[ChpBstrd]

There's also the potential effects of condensation inside the engine.

E.g. Engine contains warm, moist air. Then outside cools down and the metal is colder than the air inside. Droplets form. Process repeats as new humid air enters the engine. This would happen even if the car was never driven.

[Nutty]

Acquaintance trashed their engine.  Known defect that accumulates sludge in the engine (Kia Sportage (?) and Dodge Durango for example) so the maker has bought new engines.

They asked for proof of oil changes.  Since he didn't have the oil change receipts, nor documentation from the dealer, nor 10 minute oil change (supposedly they load this to a database that the dealers can see?), the warranty was void due to improper maintenance.  They are having to buy a new engine out of pocket (car is financed + other non Mustacheian issues).

How many of us can prove proper maintenance to utilize a factory warranty, much less an aftermarket warranty? 

My first and only new car went to the dealer for a dealer oil change.  They asked me if I wanted the spark plug wires changed on a new car?  I said no.  Do you have problems with them?  They changed them and charged me for it.  Stated on the repair ticket that I wanted the wires changed.  Solved the dealer oil change problem for me.  Dealer was investigated and shut down for customer complaints years later.  Caveat emptor.

[alohaKane]

3k-5k miles if you ask me. Yea it may seem like overdone but that's the cost of caring for your car. Remember oil is running throughout your engine and over time dirt/debris gets in there.. Also, in that note, I would start learning how to DIY that thing lol 

[ChpBstrd]

Acquaintance trashed their engine.  Known defect that accumulates sludge in the engine (Kia Sportage (?) and Dodge Durango for example) so the maker has bought new engines.

They asked for proof of oil changes.  Since he didn't have the oil change receipts, nor documentation from the dealer, nor 10 minute oil change (supposedly they load this to a database that the dealers can see?), the warranty was void due to improper maintenance.  They are having to buy a new engine out of pocket (car is financed + other non Mustacheian issues).

How many of us can prove proper maintenance to utilize a factory warranty, much less an aftermarket warranty? 

My first and only new car went to the dealer for a dealer oil change.  They asked me if I wanted the spark plug wires changed on a new car?  I said no.  Do you have problems with them?  They changed them and charged me for it.  Stated on the repair ticket that I wanted the wires changed.  Solved the dealer oil change problem for me.  Dealer was investigated and shut down for customer complaints years later.  Caveat emptor.

Yea, warranties are almost useless because there's always a way out for the dealership. Pretend they don't exist.

[ChickenStash]

I've never paid much attention to the time req's on oil changes but most of my cars get enough mileage (~5k) or heavy service that I'm changing oil once a year anyway. The issue with time is the accumulation of moisture that then creates acids that degrade bearings and seals. Not a short or medium term issue and modern PCV systems keep things fairly well sealed but if the plan is to keep the car for 15+ years then it's not a bad idea to be extra cautious. Same is true for other fluids - some research or common sense should be applied when looking at the factory service schedules and modify as needed.

When I've been under warranty (usually the tail end of a powertrain warranty or a CPO), I just keep copies of the receipts showing the oil and filter purchases with a date and record the mileage. That should be sufficient for a reputable factory warranty. Aftermarket warranties are hit/miss (mostly miss).

[SmashYourSmartPhone]

3k-5k miles if you ask me. Yea it may seem like overdone but that's the cost of caring for your car. Remember oil is running throughout your engine and over time dirt/debris gets in there..

Yes, and also you have an oil filter if you have a newer car.  I believe by the 1940s, oil filters were fairly standard.

The core oil does not "wear out," but it can be degraded through a variety of means.

If the engine has high pressure gearing (typical for motorcycle transmissions, possibly cam gears on some engines, etc), this can physically shear down the oil to a lighter weight.  It is common for motorcycles to shear oil down to a far lighter viscosity during operation.  This is not a common form of oil failure in a car or truck engine, though.

The more common death of oil is the wearing out of additive packages designed to buffer acids and other assorted chemicals that are hostile to engine internals.  Oil contains a range of things added in that do "run out" - not just the buffers, but also things like zinc that are designed as anti-wear additives (diesel oils have far more zinc and such, which is good on older engine designs with flat tappets and associated, I run diesel oil in almost all my engines except for the car).

Getting dirty is a problem, but the oil filter tends to solve that until the filter is substantially clogged and bypassing - at which point, you are likely well beyond oil change intervals to start with, and may have sludging problems (this tends engine specific, not a general purpose problem).  If you have a vehicle doing high miles, a "bypass oil filter" system can help here substantially: This is a system that diverts a portion of the high pressure oil off the pump (5-10% typically, not enough to interfere with lubrication as this much is typically bypassed by the pressure regulator anyway) though a far finer filter than the normal "full flow" filter that all oil passes through on the way to the bearings.  By not needing to filter the full oil flow, the bypass filter can be a far finer filtration media (imagine a roll of toilet paper instead of the normal filter media) and will, over time, do a far finer filtration of the oil than the normal filter can manage.

Combine a bypass oil system with regular oil analysis (Blackstone Labs or similar), and you can safely run far higher miles on an oil change than manufacturer specifications, while still maintaining proper oil behavior and additives (they will, on occasion, recommend things like a "half oil change" where you drain a few quarts out, put a few new ones in, etc).  This is most useful for things like high mileage trucks that are used for a lot of highway miles.

For "a few thousand miles a year," simply change the oil annually and call it good.

[Plugra]

Stay away from those quick change places. They hire idiots and they make a lot of mistakes.

Learn to change your own oil.  It doesn't take any longer than driving to the dealer.  Use full synthetic and a high quality filter. 

[use2betrix]

Acquaintance trashed their engine.  Known defect that accumulates sludge in the engine (Kia Sportage (?) and Dodge Durango for example) so the maker has bought new engines.

They asked for proof of oil changes.  Since he didn't have the oil change receipts, nor documentation from the dealer, nor 10 minute oil change (supposedly they load this to a database that the dealers can see?), the warranty was void due to improper maintenance.  They are having to buy a new engine out of pocket (car is financed + other non Mustacheian issues).

How many of us can prove proper maintenance to utilize a factory warranty, much less an aftermarket warranty? 

My first and only new car went to the dealer for a dealer oil change.  They asked me if I wanted the spark plug wires changed on a new car?  I said no.  Do you have problems with them?  They changed them and charged me for it.  Stated on the repair ticket that I wanted the wires changed.  Solved the dealer oil change problem for me.  Dealer was investigated and shut down for customer complaints years later.  Caveat emptor.

Yea, warranties are almost useless because there's always a way out for the dealership. Pretend they don't exist.

If someone maintains their vehicle per the manual, there’s really not much of a way out. The problem is that many people buy new vehicles and have absolutely no understanding of car maintenance or warranties. It’s also usually not the ‘dealers’ looking for a way out, but the manufacturer. Dealerships get paid to make the repairs (by the manufacturer) so it’s just more paid work for them. They also probably are happy to support warranties as it means a happier customer/better reputation.

I would venture a guess that probably 25% or more of new car owners do not maintain their vehicle, per the manual. Then they get into issues, as a previous poster mentioned, about their vehicle not being covered for warranty repairs.

Most manufacturers have relatively reasonable maintenance intervals. It’s also very reasonable that they have minimum expectations to be met to prevent damage if they are going to provide a warranty to cover repairs that could happen due to lack of those maintenance items.

I’ve owned several new vehicles over the years and have had a handful of repairs made under warranty. Never had an issue with any manufacturers.

[FINate]

I've experienced the oil contamination issue. I drive infrequently, and when I do it's often short trips. This means I almost never reach the ODO marker for changing my oil. And it means the engine doesn't get up to temperature for very long. At around 6-9 months I start to notice some oil contamination (slightly milky oil color). There are no signs of a head gasket leak, and no concerning changes to oil or coolant levels. So the most likely explanation is oil contamination from condensation. Any water in the oil is bad for the engine and can cause rust. I monitor the oil color and change when it starts to look off, which usually means 1-2x per year. IMO, at the very least you should be manually checking your oil and watching for contamination. Really, though, I would still change it at least once per year.