# How often should I change the oil in my car?

**URL:** <https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276>\
**Category:** Factual Questions\
**Created:** [March 9, 2014, 5:05pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276 "2014-03-09T17:05:12Z")\
**Posts on this page:** 14\
**Page:** 2

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**Author:** ![TSBG](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@TSBG](https://boards.straightdope.com/u/TSBG)\
**Post date:** [March 10, 2014, 6:13pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/21 "2014-03-10T18:13:52Z")

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As it happens, my owner’s manual doesn’t say how often to change the oil.

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**Author:** ![Nars\_Glinley](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nars_glinley/32/8177_2.png) [@Nars\_Glinley](https://boards.straightdope.com/u/Nars_Glinley)\
**Post date:** [March 10, 2014, 6:24pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/22 "2014-03-10T18:24:20Z")

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> [@TSBG](#):
>
> As it happens, my owner’s manual doesn’t say how often to change the oil.

Worst. Owner’s. Manual. Ever.

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**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\
**Post date:** [March 10, 2014, 6:37pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/23 "2014-03-10T18:37:51Z")

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> [@TSBG](#):
>
> As it happens, my owner’s manual doesn’t say how often to change the oil.

I went online to look at the PDF version of the manual. That doesn’t tell you how often to change the oil but the “2010 Prius: Warranty and Maintenance Guide” does. It calls for the oil to be changed every 5,000 miles.

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**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\
**Post date:** [March 10, 2014, 6:46pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/24 "2014-03-10T18:46:56Z")

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The manual for my 2000 Chrysler minivan says 7500 miles or 3 months, whichever comes first. I usually change around 5-6K, though, and usually go more than 3 months but try not to go past 4 or 5. The place that changes the oil puts in a sticker that says I need the next one in 3500 miles, which I compensate for. Before my last move, I tended to put 10K miles/year, which is less than the average, and even includes a few road trips (e.g., MI-to-FL.)

I always get at least 150K miles out of an American brand car, and they always fail in the transmission, so whatever I’m doing, it’s not too hard on the vehicle.

> [@Rick](#):
>
> When reading pay particular attention as to what qualifies as severe conditions. It is quite likely your normal commute falls into severe duty.

Why would that be? 50K miles in 4 years is pretty normal, as is a daily commute.

> [@Kenm](#):
>
> It may be a surprise to discover what “normal” means to car makers.
> 
> When it comes to warranty issues, it would be safest to assume “normal” means a car in mint condition with fresh oil and perfect fuel piped into the engine from the refinery lab next door, and running for weeks non-stop on rollers with the cruise control set at 42 mph so the transmission’s in lockup and the RPMs at 1,100, in a computer-chip-fabrication clean room at a consistent 68°F with humidity of 30 per cent. Anything else could be “severe.”

Cite?

Of course you’re BSing here, but really: normal means normal, and that’s what most people do most of the time in most places. I’ve never had an issue with warranty work in my normal driving, which is a fairly typical daily commute. Fortunately I’ve had very few cases of warranty repairs needed – which also bolsters my position that a typical commute is normal driving. Exceptions would be super heavy traffic areas causing lots of idling, or extreme temperatures or gradients (especially, big climbs before the engine warms up).

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**Author:** ![SpeedwayRyan](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@SpeedwayRyan](https://boards.straightdope.com/u/SpeedwayRyan)\
**Post date:** [March 10, 2014, 7:08pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/25 "2014-03-10T19:08:11Z")

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> [@Nars\_Glinley](#):
>
> My wife’s Subaru recommends full synthetic every 7500 miles. I’m grumbling about it but doing it anyway.

Could be worse – I just changed my Subaru’s oil at 7455 miles or so (the 7500 mile service), and that was the SECOND oil change…with full synthetic. It’s a turbocharged WRX, and they are pretty serious about the oil change intervals on those cars, apparently.

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**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\
**Post date:** [March 10, 2014, 7:12pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/26 "2014-03-10T19:12:43Z")

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> [@Learjeff](#):
>
> Why would that be? 50K miles in 4 years is pretty normal, as is a daily commute.
> 
> Cite?
> 
> Of course you’re BSing here, but really: normal means normal, and that’s what most people do most of the time in most places. I’ve never had an issue with warranty work in my normal driving, which is a fairly typical daily commute. Fortunately I’ve had very few cases of warranty repairs needed – which also bolsters my position that a typical commute is normal driving. Exceptions would be super heavy traffic areas causing lots of idling, or extreme temperatures or gradients (especially, big climbs before the engine warms up).

I got a cite right here.  
The owner’s manual for Hyundai states:  
Severe usage includes  
A. Short trips  
B. Stop and go traffic  
C. Hot weather

So you normal commute in LA traffic is:  
Short trip? Quite likely  
Stop and go? Check  
Hot weather? Check  
So your normal commute isn’t normal usage.

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**Author:** ![Kenm](https://avatars.discourse-cdn.com/v4/letter/k/bc79bd/32.png) [@Kenm](https://boards.straightdope.com/u/Kenm)\
**Post date:** [March 10, 2014, 7:19pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/27 "2014-03-10T19:19:23Z")

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> [@Learjeff](#):
>
> Cite?

I read of car makers’ “normal” and “severe” warranty ripoff decades ago, and it saved my bacon a couple of times because I keep my receipts.

This 2009 [**cite**](http://newsroom.aaa.com/2009/10/aaa-study-finds-most-motorists-drive-under-severe-conditions-do-not-realize-it/) is more recent, though.

What? You drove in city traffic in summer? That’s severe. No warranty.

Oh oh. There are stones stuck in the tread. You drove on gravel. That’s severe. No warranty.

Oh oh. There’s mud on the fenders. You drove on mud. That’s severe. No warranty.

If driving to the store on a summer afternoon is severe service, why bother with so-called normal? They’re weasels and my BSing post really isn’t.

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**Author:** ![TSBG](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@TSBG](https://boards.straightdope.com/u/TSBG)\
**Post date:** [March 10, 2014, 7:22pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/28 "2014-03-10T19:22:15Z")

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Thanks Dewey, it occurred to me that there ought to be some source for that info but I hadn’t got around to searching through my files yet.

Also, the premise of my post turns out to be mistaken–I did the math wrong and my Prius IS suggesting a change after 3K. Does it know something?

Also, regarding the discussion of “extreme” conditions–the VW comes with 3 years of oil changes included, at 10K intervals. We live in LA. If LA commuting is extra-hard on a car, isn’t VW risking unhappy customers if the oil is changed on their schedule and the car then has problems?

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**Author:** ![chargerrich](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chargerrich/32/5399_2.png) [@chargerrich](https://boards.straightdope.com/u/chargerrich)\
**Post date:** [March 10, 2014, 8:47pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/29 "2014-03-10T20:47:14Z")

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> [@TSBG](#):
>
> This seems like such an obvious topic of discussion that I’m sure it’s already been addressed, but the search function isn’t working for me.
> 
> I have a 2010 Prius coming up on 50K. The car wants me to change the oil and it’s almost 5K since the last change. I was brought up to change oil every 3K and that’s what I usually do, just forgot to do it this time around. But my wife’s Jetta says to change it every 10K and I’ve seen other places that synthetic oil (which I use in the Prius) only needs to be changed every 10K.
> 
> What’s the Straight Dope?

While the Jiffy Lubes and their ilk love to keep touting this 1940s logic, the fact is most modern cars can EASILY go 5-10k on an oil change. In fact today’s oil viscosity is not the limiting factor but the filter generally is.

Changing every 3k is throwing money away but if your car is under a factory warranty you will want to follow that.

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**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\
**Post date:** [March 10, 2014, 9:23pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/30 "2014-03-10T21:23:45Z")

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> [@Kenm](#):
>
> If driving to the store on a summer afternoon is severe service, why bother with so-called normal? They’re weasels and my BSing post really isn’t.

My truck’s long out of warranty, but I know what you’re talking about.

Here are a few of the things called out as severe service in my manual that seem to not be so “severe”:

[ul]  
[li]Temperatures below 32F[/li][li]50% of driving over 90F[/li][li]Stop and go driving[/li][li]Short trips under 10 miles[/li][/ul]

I live in Dallas, for God’s sake! Every freaking day from about June through mid-September, my afternoon commute is over 90F, and in December through February, temperatures below 32 in the morning are not uncommon either. Stop and go driving is the norm, and my commute is just about 9.5 miles one-way.

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**Author:** ![Nars\_Glinley](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nars_glinley/32/8177_2.png) [@Nars\_Glinley](https://boards.straightdope.com/u/Nars_Glinley)\
**Post date:** [March 10, 2014, 9:44pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/31 "2014-03-10T21:44:40Z")

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> [@SpeedwayRyan](#):
>
> Could be worse – I just changed my Subaru’s oil at 7455 miles or so (the 7500 mile service), and that was the SECOND oil change…with full synthetic. It’s a turbocharged WRX, and they are pretty serious about the oil change intervals on those cars, apparently.

I was _supposed_ to have had hers changed at 3750 but I wasn’t paying attention and it got skipped. Her car isn’t even a turbo. I hope I didn’t screw myself. It seems unlikely but I guess only time will tell.

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**Author:** ![Kenm](https://avatars.discourse-cdn.com/v4/letter/k/bc79bd/32.png) [@Kenm](https://boards.straightdope.com/u/Kenm)\
**Post date:** [March 10, 2014, 10:21pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/32 "2014-03-10T22:21:00Z")

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> [@Nars\_Glinley](#):
>
> I was _supposed_ to have had hers changed at 3750 but I wasn’t paying attention and it got skipped. Her car isn’t even a turbo. I hope I didn’t screw myself. It seems unlikely but I guess only time will tell.

Look up Blackstone Labs or some other oil-analysis lab and send them a sample of the oil. If the analysis comes back saying the oil was still serviceable, you’ll have righteousness and a good defence on your side if it comes to any warranty issue.

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**Author:** ![epbrown01](https://avatars.discourse-cdn.com/v4/letter/e/7ba0ec/32.png) [@epbrown01](https://boards.straightdope.com/u/epbrown01)\
**Post date:** [March 11, 2014, 4:40pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/33 "2014-03-11T16:40:46Z")

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> [@chargerrich](#):
>
> Changing every 3k is throwing money away but if your car is under a factory warranty you will want to follow that.

One way to extend service intervals is to buy a car with maintenance included. BMW pundits love to point out that when BMW started including “free” maintenance across the model line, oil, brake pads, and coolant started lasting a lot longer. 🙂

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**Author:** ![leftfield6](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leftfield6/32/18780_2.png) [@leftfield6](https://boards.straightdope.com/u/leftfield6)\
**Post date:** [March 11, 2014, 5:44pm UTC](https://boards.straightdope.com/t/how-often-should-i-change-the-oil-in-my-car/683276/34 "2014-03-11T17:44:31Z")

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> [@TSBG](#):
>
> Thanks Dewey, it occurred to me that there ought to be some source for that info but I hadn’t got around to searching through my files yet.
> 
> Also, the premise of my post turns out to be mistaken–I did the math wrong and my Prius IS suggesting a change after 3K. Does it know something?
> 
> Also, regarding the discussion of “extreme” conditions–the VW comes with 3 years of oil changes included, at 10K intervals. We live in LA. If LA commuting is extra-hard on a car, isn’t VW risking unhappy customers if the oil is changed on their schedule and the car then has problems?

According to [this](http://priuschat.com/threads/2010-prius-maintenance-schedule-us.93946/), you Prius should get 10K oil changes. The Change Oil indicator on your dash likely was not reset by the last person who changed your oil. On the Prius, it is purely triggered by mileage, not by any chemical analysis of the remaining life of the oil.

[And here](http://priuschat.com/threads/howto-resetting-the-oil-maintenance-required-indicator.70054/) is how to reset the darn light.

My ex-wife’s 04 Civic Hybrid gets 10K changes with Mobil 1 0-20. Currently has 160k on it and gong strong. The oil still looks golden colored after 10K.

Good luck with the Prius.

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