Engine oil change interval: Why 6 months?

TJim

TJim

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Hey guys!

I use 10W40 Valvoline Maxlife (synthetic blend). I have a 2.4L engine.

My TJ averages 4000-5000 miles per year.

For example: this year I have roughly 2500 miles since I changed the engine oil 7 months ago.

Many people claim that they change at around 5000 miles or 6 months, whichever comes first.

Can anyone explain to a beginner why the engine oil should be changed after 6 months and not wait 1 year, since my miles are so low? So I don't change my engine oil after only 2000-2500 miles?
 
You’re putting way too much thought into this, I promise you.

Pick an interval (for me it’s 5k miles) and change the oil. Unless it’s been sitting for years and years, that’s all you need to focus on.

That’s it, plain and simple. 👍
 
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Chris said:
You’re putting way too much thought into this, I promise you.

Pick an interval (for me it’s 5k miles) and change the oil. Unless it’s been sitting for years and years, that’s all you need to focus on.

That’s it, plain and simple. 👍
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Gollywomper said:
My Jeep does not see 5000 a year. It gets fresh oil once a year whether it needs it or not. 😜
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So once a year is acceptable, since I don't drive it more than 5000 miles per year.

No reason to change it at 6 months if mileage is low.

Thanks for the answers.
 
In the 1970,s we didn't change the oil we just kept topping it up, in fact we didnt do any sort of service unless something broke or the car wouldn't start

I had a 2000 Holden pickup from new I used to carry my trade tools and when I gave up being self employed in mid 2008 I decided to never lift the hood again but still used it as a DD to work and back, in 2017 the timing belt broke, luckily it was an Isuzu motor as they self level when a belt goes so no damage, I gave it to a work friend he put a new timing belt on it and changed the oil & plugs then sold it still running good last year, 9 years on the same oil It was a 2.2 Petrol Isuzu.

The reason for this true story is the fact I believe we have been conditioned to have oil changes with a service every 6 months when it is not necessary. 6 month or 5000 intervals are for vehicles under warranty or fleet vehicles and for people who never lift their hood or check their tyre pressure. Change your oil when it gets black or very dark.

I have not driven my TJ 5000 miles yet in the 16 months I have had it but I have done 3 oil and filter changes? lol.
 
I drive a 2003 TJ. I only drive 2000 miles a year nowadays. Currently she has 130k miles on the odometer.

I was changing oil once a year whether it needed it or not. The last change I had my oil analyzed by Blackstone.

https://www.blackstone-labs.com
They replied oil looks great and said next time wait until 5000 miles for the change and send another sample.

It is coming up on two and a half years.

I will be sending in another sample.

The results will be interesting, but I am expecting the same positive result.
 
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I had never even heard of people having their vehicles used oil analysed in a lab until I joined this forum.
I think in Australia its only available for industrial purposes?
I am sure Apple will have an App for it soon though :)
 
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Chris said:
You’re putting way too much thought into this, I promise you.

Pick an interval (for me it’s 5k miles) and change the oil. Unless it’s been sitting for years and years, that’s all you need to focus on.

That’s it, plain and simple. 👍
Click to expand...
:eek:OH MY GOD CHRIS ! YOU CANT GO 5K MILES, I THINK THE BOOK SAYS 3500 ! in another thread about diesel oil changes i got chastised because i go 10k miles on my ecodiesel ! the fucking manual says 10k and the oil change light comes on at 10k. but we know just like milk oil spoils and loses all lubricating ability 😉😉 ! every 5k miles i drop my TJ at the walmart and tell them change the oil, rotate and balance the tires ! only way i would change it before 5k miles at 6 months would be if i had a engine under warranty because if you dont and you have a problem, they would damn sure do their best not to warranty your motor because of it !
 
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Fishtaco said:
I had never even heard of people having their vehicles used oil analysed in a lab until I joined this forum.
I think in Australia its only available for industrial purposes?
I am sure Apple will have an App for it soon though :)
Click to expand...
big rigs and some diesel owners have done it for many years. when you have a engine that holds 3, 4, or more gallons it can get expensive real fast. some big trucks go 40k miles or more between changes, they send in a sample and they tell them when it needs to be changed !
 
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I change mine every 4k.
Newer cars with these stupid ass oil life monitor systems are rediculous. I've had customers put 7500-10k miles on their vehicles without doing an oil change. And their oil life is still reading 30%
 
williambmac said:
I change mine every 4k.
Newer cars with these stupid ass oil life monitor systems are rediculous. I've had customers put 7500-10k miles on their vehicles without doing an oil change. And their oil life is still reading 30%
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i've never seen one that goes beyond 10k miles, but like i said my manual also says 10k so thats what i go with
 
tr21triton said:
:eek:OH MY GOD CHRIS ! YOU CANT GO 5K MILES, I THINK THE BOOK SAYS 3500 ! in another thread about diesel oil changes i got chastised because i go 10k miles on my ecodiesel ! the fucking manual says 10k and the oil change light comes on at 10k. but we know just like milk oil spoils and loses all lubricating ability 😉😉 ! every 5k miles i drop my TJ at the walmart and tell them change the oil, rotate and balance the tires ! only way i would change it before 5k miles at 6 months would be if i had a engine under warranty because if you dont and you have a problem, they would damn sure do their best not to warranty your motor because of it !
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Haha, I’ve done 7k miles between oil changes. Admittedly doing it at 5k is probably even premature, but I figure if you’re off-roading and getting really dirty, it won’t hurt.
 
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LONGJP2 said:
Are you seeing lots of engine failures because of this?
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Fuck yes. I have rebuild at least 100 motors working for GM, and that is not counting the complete engine replacements that I have done.
2.4 Equinox engines are high up on the list. You can get over 7500 miles on them before your oil change light comes on. People will squeak every mile they can out of it.
The oil rings gum up and stick in the ring land, next thing you know the vehicle is consuming oil at 2 quarts every 1k miles.

5.3 k truck motors the same thing, thats if you don't end up pulling it down to replace the cam and lifters first. The AFM lifters always crap out.

1.4 and 1.5 motors also fail but not as often. They usually crack the ring land on #1 piston, then you have a dead hole. This is usually caused by detonation though. But I have torn them down for oil consumption also.
 
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An engine builder I've dealt with recently said ignore the time with modern oils and just use miles/km as a metric. That's what I do now. You could send your oil out for analysis and find out for sure. I don't consider time with respect to oil changes anymore.
 
pagrey said:
An engine builder I've dealt with recently said ignore the time with modern oils and just use miles/km as a metric. That's what I do now. You could send your oil out for analysis and find out for sure. I don't consider time with respect to oil changes anymore.
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The oil analysis also provides a check on engine health. Coolant in the oil, unusual engine wear other contaminants. This was the primary reason i decided to give it a try at 125k.

Previously i was in the once a year or 3k miles group using mobile 1. This coming oil change I am going to use Pennzoil dino.
 
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