More Evidence That Doesn't Support 10K Oil Changes

[Bill7]

10k+ OCIs are marketing and sales driven schemes. They're not designed for optimal drivetrain functions and longevity.

With a Dexos 1 Gen 3 approved full synthetic 5W-30, I only go 4k/6 months (whichever comes first) on my Odysseys,
and 5k/6 month on my Corolla. I would never dare go past 5k on any vehicle I care about.

UOA's don't measure deposit buildup varnish or sludge accumulation, so people who do a UOA with a 10k OCI and see low wear metals are given a false sense of security. It's not wear metals that matter, its varnish / sludge accumulation.

 

[BHopkins]

With a Dexos 1 Gen 3 approved full synthetic 5W-30, I only go 4k/6 months (whichever comes first) on my Odysseys,
and 5k/6 month on my Corolla. I would never dare go past 5k on any vehicle I care about.

UOA's don't measure deposit buildup varnish or sludge accumulation, so people who do a UOA with a 10k OCI and see low wear metals are given a false sense of security. It's not wear metals that matter, its varnish / sludge accumulation.

Yes and no. Varnish and sludge, particularly sludge, leads to engine failure. But so can wear metals. That's why I posted this. A spotless engine, totally free of sludge and varnish, is easily obtainable with 10k mile oil changes.

There is overwhelming evidence out there, that shows it is a fable to believe that oil has to be changed at 5k miles to avoid varnish and sludge. Perhaps there are engines out there that do require a more frequent oci. But not the one below.

I'm not real good with taking pictures with my bore scope, but here is a picture down the oil fill, on my Merecedes E350. 106k miles, with 10k mile oci, since I bought the car with 46k miles on it. All oil changes have been M1 0W-40 European Car Formula, which as pointed out earlier by @Astro14, meets the Mercedes 229.5 specification. Not a trace of varnish, let alone sludge.

So I'm very skeptical of Youtube videos that claim that an engine full of sludge was maintained to the manufacturer's service schedule.


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[Astro14]

With a Dexos 1 Gen 3 approved full synthetic 5W-30, I only go 4k/6 months (whichever comes first) on my Odysseys,
and 5k/6 month on my Corolla. I would never dare go past 5k on any vehicle I care about.

UOA's don't measure deposit buildup varnish or sludge accumulation, so people who do a UOA with a 10k OCI and see low wear metals are given a false sense of security. It's not wear metals that matter, its varnish / sludge accumulation.

People who do a UOA are looking at much more than wear metals, there is the matter of TBN, viscosity, and fuel dilution.

Just like the original poster, you are focused on one thing, and ignore important aspects of the topic, to make the short OCI argument.

If the TBN is strong, you’re not getting sludge - chemically, the alkalinity prevents sludge formation.

So, a UOA can absolutely help you determine the appropriate OCI for your engine, your use, and your oil.

Here is an engine that went 34,000 on the oil - and is spotless. No sludge.

https://bobistheoilguy.com/forums/t...-total-34-000-miles-on-hpl-hdeo-5w-20.377792/

Shall we ignore all other important, salient, factors, and put this example in the “short intervals cause sludge” category?

Because clearly, extreme interval cause super-clean engines.

 

[Bill7]

Yes and no. Varnish and sludge, particularly sludge, leads to engine failure. But so can wear metals. That's why I posted this. A spotless engine, totally free of sludge and varnish, is easily obtainable with 10k mile oil changes.

There is overwhelming evidence out there, that shows it is a fable to believe that oil has to be changed at 5k miles to avoid varnish and sludge. Perhaps there are engines out there that do require a more frequent oci. But not the one below.

Perhaps if I were leasing a car or were only going to keep the car for 5 years, a 10k OCI might make sense,
as I wouldn't care about the long term health of the car.

But, since I like to drive my vehicles for 200k miles, I prefer DIY 5k/6 month OCI (whichever comes first) with a low cost full synthetic oil.
Clean "unstuck" piston rings are the key to engine longevity in my opinion.

Also, ATF drain and fills every 30k miles are good maintenance practice, and cost almost nothing if you do them yourself.

 

[billt460]

There is overwhelming evidence out there, that shows it is a fable to believe that oil has to be changed at 5k miles to avoid varnish and sludge. Perhaps there are engines out there that do require a more frequent oci. But not the one below.

Yes, but do you believe it?

 

[buster]

Everyone wants a simple, straightforward answer when in reality there just isn't one. Whether it's the Nissan guy saying change it every 3k, to your OLM to Joe Schmoe at Autozone saying every 500 miles to oil marketers claiming 25k miles. So many things to consider, including how long you want to keep the car and what is acceptable to you for your own standards.

If I were to help someone that knows nothing about oil or cars, I would simply tell them to use an oil that meets the specification in their owner's manual and change it based off the severe service interval just for cushion.

 

[billt460]

Why didn't you say so a 178 posts ago?

Hey, that first post has 11 likes. You better grab a wrench and scoot under that puppy with a pan. You can thank me later for how good you'll feel.

Give me the number to your local Autozone. I'll phone ahead and let them know you're on your way!

 

[Bill7]

Everyone wants a simple, straightforward answer when in reality there just isn't one. Whether it's the Nissan guy saying change it every 3k, to your OLM to Joe Schmoe at Autozone saying every 500 miles to oil marketers claiming 25k miles. So many things to consider, including how long you want to keep the car and what is acceptable to you for your own standards.

If I were to help someone that knows nothing about oil or cars, I would simply tell them to use an oil that meets the specification in their owner's manual and change it based off the severe service interval just for cushion.

Perhaps a 5k/6 month OCI (whichever comes first) with full synthetic could be a 1 size fit's all approach for most vehicles.

But for my 3 Odyssey's with VCM enabled, 5k OCI is too long, due to VCM having extreme hot spots on front cylinder heads and a poorly designed PCV system, so max OCI with the Odyssey's is 4k OCI. I already have a severe case of varnish after 4k to 5k OCI, so perhaps 3k OCI would have been better.

 

[burbguy82]

I was trying to make this point - that using only the OCI, and ignoring other factors, leads to specious conclusions.

The personal experience is true - I had a sludged engine, that got 5,000 mile oil changes. Absolutely true.

And that conclusion is wrong - it wasn’t the short OCI that led to problems. It was a combination of factors.

Clearly, oil is not oil (as some have recently claimed) and specification matters. The engine itself needs a better quality oil than was being used by well-intentioned “mechanics” who used 15W40 conventional in a Volvo engine. Wrong spec. Even though it was “good diesel oil, with more detergents” as the owner was told.

Wrong oil, at short interval resulted in sludge. That’s the XC-90.

Same engine in the 2002 V70T5 - long drain interval with the right oil = no sludge.

Identical engines, so, we have controlled for that. Both engines see a mix of in town and highway driving. So, no difference in use. Both in Virginia Beach, so, no weird climate differences. Yet, here is the result of identical engines with over 200,000 miles:

Short interval on conventional = sludge.

Long interval on A3/B4 = clean.

I find this entire discussion of oil change interval, in isolation, without regard to engine, operating conditions, or oil specification, to be mildly ridiculous. So I posted a true example, which ignored those same factors, and the result is, well, mildly ridiculous.

If you take things out of context, and you fail to account for a multitude of variables that influence the outcome, then the result is pointless.

100% agreed.

That is why I wonder why some ask: "what is the best oil"?

This is a ridiculous question, as it has the least to so with the oil, and more to do with the countless other factors you stated.

 

[SubieRubyRoo]

Perhaps if I were leasing a car or were only going to keep the car for 5 years, a 10k OCI might make sense,
as I wouldn't care about the long term health of the car.

But, since I like to drive my vehicles for 200k miles, I prefer DIY 5k/6 month OCI (whichever comes first) with a low cost full synthetic oil.
Clean "unstuck" piston rings are the key to engine longevity in my opinion.

Also, ATF drain and fills every 30k miles are good maintenance practice, and cost almost nothing if you do them yourself.

Have you read any of @wwillson ‘s threads on his vehicles’ UOAs, their use & monitoring protocol, and the subsequent results?

Or are you just confirming what astro14 asked you about your pre-existing bias and refusal to accept the null hypothesis that short OCIs are not the only path to engine cleanliness and longevity? Asking for a friend.

 

[OilUzer]

100% agreed.

That is why I wonder why some ask: "what is the best oil"?

This is a ridiculous question, as it has the least to so with the oil, and more to do with the countless other factors you stated.

According to my signature, the best oil is a shorter OCI.

 

[billt460]

So...... Who here has run into engine problems because they changed their oil too often?

 

[Glenda W.]

So...... Who here has run into engine problems because they changed their oil too often?

Me. Stripped drain plug threads….

 

[350Rocket]

My 2005 Tacoma doesn't even have an OLM, just a yellow light that comes on in 5000 miles after it's reset. That motor doesn't burn any oil either.

It also calls for 5w30 and that engine never was known for oil usage.
The ones that were (2007+ Camry 2.4 and 2009+ Corolla etc with 1.8) called for 0w20. Not sure if they called for 10k mile oil changes before that viscosity change but I'm sure someone here knows.

 

[TiGeo]

So...... Who here has run into engine problems because they changed their oil too often?

Who here has run into engine problems using whatever OCI they use?

 

[ZeeOSix]

It also calls for 5w30 and that engine never was known for oil usage.
The ones that were (2007+ Camry 2.4 and 2009+ Corolla etc with 1.8) called for 0w20.

If it did call for 0W-20, it would have got 5W-30. Yeah, that engine seems to be bullet proof.

 

[buster]

I am in the "it depends" camp, but I'm posting to show that it can be done.

Background:

"2012 Cruze Eco 1.4L Turbo. This car has seen nothing but AMSOIL Signature Series 5W-30 since 2013, and has been tuned since as well, first with Trifecta then with BNR, making about 50hp and 70lb-ft more power *to the wheels.* Starting in about 2015, the car was used to tow my 14' boat as well as my utility trailer and various uhaul trailers. Since I started working from home full time in 2015, most of the driving was short trips, wide open throttle to redline daily.
At 72k miles, I pulled the cams to upgrade valve springs. The oil in service at the time of this disassembly had 12,500 miles and 2 years on it, about 1/4 of which was with a trailer behind it and the rest of it hitting max boost daily. I stopped caring about fuel economy once I stopped commuting. The oil change prior to that went 15,622 miles and 18 months, and all oil changes before that were at 10,000-15,000 miles (dealer drained it a couple times to service the oil pan and PCV system or they'd all have been 15k miles)."

 

[350Rocket]

If it did call for 0W-20, it would have got 5W-30. Yeah, that engine seems to be bullet proof.

A newer 4 runner is on my short list of vehicles if I ever had to replace my 2005 Silverado, just because of that engine and transmission.

 

[TurboZedd-R]

How many hours and miles does the Honda OLM typically arrive you at? Do you know if it's as advanced as say GM's? If the OLM isn't properly designed (doesn't take into account all the necessary parameters) or the OEM doesn't spec a sufficiently robust lubricant for the interval the IOLM is going to arrive at based on its programmed parameters, that's not really a condemnation of the IOLM or the IOLM concept but rather of the OEM.

My 2024 type R is at 60% olm and almost 6k miles.... no starts under freezing, but 5x weekly 2 mile trips to my local gym and a 20 mile commute to work.

 

[350Rocket]

Thank god this isn't an EU forum as these debates over OCI's will involve same numbers but in kilometers. "My BMW M6 is a high performance engine and I mush change my oil every 5k km over that ridiculous 10k or even 15k km interval as it's just sending them to an early grave". Yes folks, I've seen that argument. 5k km interval.

What's the problem with kilometers? Americans are basically the only ones not using metric. I don't have a problem with miles, converting is easy. But feet and inches, I can't understand why in this day and age anyone would use it.