How far can you really go between oil changes (using conventional oil)

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kitatech

Senior member
Jan 7, 2013
484
3
81
railer:
I would suggest you do check your manual, because a 10k+ mile OCI seems a bit much for conventional oil, regardless of what the OLM says....just sayin'
 

Throckmorton

Lifer
Aug 23, 2007
16,829
3
0
Is this going to be a weekly topic now?

Follow your manual. My manual, AFAIK, does not make a distinction between dino and synthetic oil. It states to follow the OLM, which I will do because I don't have OCD, nor do I believe that I know more than the people who engineered the car.

In my case that's probably around 10k - 13k miles on dino oil.

The engineers aren't the ones who set the interval or calibrate the OLM
 

kitatech

Senior member
Jan 7, 2013
484
3
81
Is this going to be a weekly topic now?

...I guess...and it's not unusual...though...

...it would be nice of original posters (like fuzzybabybunny) to respond to pages of posts made on their behalf...
 

Meghan54

Lifer
Oct 18, 2009
11,684
5,228
136
Yeah, nearly all the contaminants are removed from better refinement procedures. The more pure the oil, the longer it lasts.


In truth, the base oil really doesn't wear out, it's the additives that do--all those friction/anti-scuff modifiers, viscosity additives/modifiers, detergents, dispersant additives, etc.

This is borne out by testing done by U. S. Bureau of Standards, various oil companies, the U. S. Air Force, and many others.
 

Tsavo

Platinum Member
Sep 29, 2009
2,645
37
91
Modern standard oil is so refined now that it's about as good as synthetic oil was 10 years ago. You're seeing newer cars switching back to standard oil as a result.

+1.

My turbos still get synthetic, though. My NA light-duty stuff gets regular oil these days.

Engines and oils are so good these days...amazingly good. The only thing I've changed since 2005 (aside from normal wear items and fluids) is...a single thermostat, and nothing in the previous 5 years.
 

railer

Golden Member
Apr 15, 2000
1,552
69
91
railer:
... a 10k+ mile OCI seems a bit much for conventional oil, regardless of what the OLM says....just sayin'

Based on what data? My 2009 G8 GT manual does not call for synthetic. It does direct me to change the oil at the direction of the OLM, which I will do. It also states that the oil should be be changed annually if the OLM does not call for an oil change. I'm at approx 5k now, and my OLM shows 39% oil life left. Probably around 8.5 - 9k miles is when it will be calling for my next oil change. It's an 8.8 quart sump, which probably helps.

The engineers aren't the ones who set the interval or calibrate the OLM
Really? Now how would you happen to know this? My current employer, and my previous employer, and every employer that I've ever heard of, relies on their technical department to provide guidance and input towards matters of a technical nature. It is your assertion that the automakers of the world do not follow this convention? Please provide data.

This article: http://www.edmunds.com/car-care/stop-changing-your-oil.html quotes a Matt Snider, who is a project engineer in GM's Fuels and Lubricants Group. You might think that he might know something about recommending an oil change interval, or you might rely on the advice of "Jim from the internet", who has "changed his oil every 1500 miles and never had a problem." Whatever.

Kids at home: Do follow your manual. Do not listen to random anonymous internet people.
 
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Jimzz

Diamond Member
Oct 23, 2012
4,399
190
106
Based on what data? My 2009 G8 GT manual does not call for synthetic. It does direct me to change the oil at the direction of the OLM, which I will do. It also states that the oil should be be changed annually if the OLM does not call for an oil change.


Really? Now how would you happen to know this? My current employer, and my previous employer, and every employer that I've ever heard of, relies on their technical department to provide guidance and input towards matters of a technical nature. It is your assertion that the automakers of the world do not follow this convention? Please provide data.

This article: http://www.edmunds.com/car-care/stop-changing-your-oil.html quotes a Matt Snider, who is a project engineer in GM's Fuels and Lubricants Group. You might think that he might know something about recommending an oil change interval, or you might rely on the advice of "Jim from the internet", who has "changed his oil every 1500 miles and never had a problem." Whatever.

Kids at home: Do follow your manual. Do not listen to random anonymous internet people.


Engineers recommend things the bean counters then decide how far to push it. Remember it only has to last as long as the factory warranty and also the basic extended warranty.

You think a engineer said to go 7500 miles on Toyota engines with regular oil that sludged up? You think a engineer said that V6 Hondas were ok with the auto trans they were fitted to? You think a engineer said that cars sold in the US should get 5w20 while every where else that does not have CAFE should get 5w30?

All things have a spec and range. They can handle so much heat, rpms, etc... Now the bean counters come in and say the average person only drives their car hard or at the peak of this spec/range X percent of the time. As such the auto trans in the Hondas should last at least the length of a extended warranty, or most will not have sludge issues in the Toyotas engines, etc...

And how long does that engineer keep his car? If its only 60k or less then 15k oil changes today are fine. If it was drive it till the wheels fall off I bet he would drop that number down some. Is this same engineer going to cover my engine for 200k for leaks and any other damage if I do 15k oil changes?
Don't get me wrong I think most over change their oil and I use to be a mechanic. Trying to talk people to go to 5000miles on regular you think I was trying to kill their first born. Let alone if they used synthetic or had a large oil sump and I told them to go even longer.
 
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Throckmorton

Lifer
Aug 23, 2007
16,829
3
0
Based on what data? My 2009 G8 GT manual does not call for synthetic. It does direct me to change the oil at the direction of the OLM, which I will do. It also states that the oil should be be changed annually if the OLM does not call for an oil change. I'm at approx 5k now, and my OLM shows 39% oil life left. Probably around 8.5 - 9k miles is when it will be calling for my next oil change. It's an 8.8 quart sump, which probably helps.


Really? Now how would you happen to know this? My current employer, and my previous employer, and every employer that I've ever heard of, relies on their technical department to provide guidance and input towards matters of a technical nature. It is your assertion that the automakers of the world do not follow this convention? Please provide data.

This article: http://www.edmunds.com/car-care/stop-changing-your-oil.html quotes a Matt Snider, who is a project engineer in GM's Fuels and Lubricants Group. You might think that he might know something about recommending an oil change interval, or you might rely on the advice of "Jim from the internet", who has "changed his oil every 1500 miles and never had a problem." Whatever.

Kids at home: Do follow your manual. Do not listen to random anonymous internet people.

Explain to me why BMW increased their interval from 7500 to 15000 miles at the exact same time they started doing free maintenance. Do you think that just happened to be the point at which the engineers changed their mind? Or do you think it's more likely that they set the interval to 15000 to save labor costs?
 

kitatech

Senior member
Jan 7, 2013
484
3
81
Based on what data?

The only problem I have with data is that they're not based on MY engine, MY driving habits, etc...Every engine is different as is the driver...and erring on the side of shorter OCIs is better to my mind than erring on the side of the road waiting for a tow truck....that's all...
 

mmntech

Lifer
Sep 20, 2007
17,501
12
0
We used to change the oil in the rental cars every 12,000km. That stuff was jet black when it came out. Mind you those cars were driven hard.
 

railer

Golden Member
Apr 15, 2000
1,552
69
91
Engineers recommend things the bean counters then decide how far to push it. Remember it only has to last as long as the factory warranty and also the basic extended warranty.

You think a engineer said to go 7500 miles on Toyota engines with regular oil that sludged up? You think a engineer said that V6 Hondas were ok with the auto trans they were fitted to? You think a engineer said that cars sold in the US should get 5w20 while every where else that does not have CAFE should get 5w30?

Even a bean counter that flunked out of community college would never propose what you describe. It makes no financial sense for a company to purposely encourage a maintenance interval that is detrimental to their product. How many car and truck ads, both print and TV, have you seen in your life? 1000's? 10's of thousands? Now how many of those ads have ever mentioned a longer interval oil change as a selling point. I have never seen one in my life. If you have, please link to it.
On the contrary, how many times to you see JD Power reports, resale value (which is a direct function of perceived longevity), % of cars still on the road, etc. That's the type of metric that sells cars and makes money for auto manufacturers. The notion that an automaker would recommend an oil change interval which nets them zero dollars and zero additional sales, but destroys their reputation and eventually costs them 10's of millions of dollars in sales and drives them to bankruptcy, is preposterous.
It not only fails the logic test of a rational consumer, it also fails the logic test of any and all bean counters out there. No one at any level of accounting, marketing, sales, or engineering would ever encourage such a strategy....because it makes no financial sense at all.

This is linked every week when this same exact topic comes up, and I'll link it again:
http://www.edmunds.com/pontiac/g8/2...tiac-g8-gt-lab-results-on-13000-mile-oil.html
This is a Pontiac with 13k on the oil with what I believe to be dino oil (since that is what is recommended for the car, and the article doesn't state otherwise), and the oil tests fine. Blackstone even says that they could have got another 2k miles out of the oil.

The moral of the story is the same: Follow your owners manual.


Edit: And as for BMW....I'm not a follower so I have no idea. They are the only manufacturer that I'm aware of that performs some type of rudimentary analysis on their oil in the car, and I assume they recommend a synthetic if they're pushing these changes out to 15k? I assume the 15k miles is an absolute maximum, and if their OLM calls for an oil change prior to that then they will perform the oil change? Like I said I don't know the details about BMW's recommendations, but same logic applies: They're not going to trash their worldwide reputation over some $40 oil change, or lack thereof. Any bean counter who ever recommended such absurdity would be fired immediately for having the logical acuity of a brain damaged monkey. That would be a money LOSING idea for any car manufacturer, and they would never do it.

Follow your manual.
 
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Throckmorton

Lifer
Aug 23, 2007
16,829
3
0
Even a bean counter that flunked out of community college would never propose what you describe. It makes no financial sense for a company to purposely encourage a maintenance interval that is detrimental to their product. How many car and truck ads, both print and TV, have you seen in your life? 1000's? 10's of thousands? Now how many of those ads have ever mentioned a longer interval oil change as a selling point. I have never seen one in my life. If you have, please link to it.
On the contrary, how many times to you see JD Power reports, resale value (which is a direct function of perceived longevity), % of cars still on the road, etc. That's the type of metric that sells cars and makes money for auto manufacturers. The notion that an automaker would recommend an oil change interval which nets them zero dollars and zero additional sales, but destroys their reputation and eventually costs them 10's of millions of dollars in sales and drives them to bankruptcy, is preposterous.
It not only fails the logic test of a rational consumer, it also fails the logic test of any and all bean counters out there. No one at any level of accounting, marketing, sales, or engineering would ever encourage such a strategy....because it makes no financial sense at all.

This is linked every week when this same exact topic comes up, and I'll link it again:
http://www.edmunds.com/pontiac/g8/2...tiac-g8-gt-lab-results-on-13000-mile-oil.html
This is a Pontiac with 13k on the oil with what I believe to be dino oil (since that is what is recommended for the car, and the article doesn't state otherwise), and the oil tests fine. Blackstone even says that they could have got another 2k miles out of the oil.

The moral of the story is the same: Follow your owners manual.

It's not a selling point... it's a way for them to save money when they provide free maintenance. Which do you think costs BMW more, changing your oil for free 4 times over 60k miles, or 8 times?

Still waiting for you to provide an explanation of why BMW engineers suddenly changed their minds and decided on 15k instead of 7.5k at exactly the same time they started offering free maintenance.
 

railer

Golden Member
Apr 15, 2000
1,552
69
91
Read what I already said about BMW.
All auto manufactures on the face of the earth have longer recommended oil change intervals, and none of them provides free maintenance, besides BMW, apparently.

I have no idea what BMW actually recommends, and I'm not going to bother to find out since I don't own a BMW. BMW is not going to ruin their reputation over some $40 oil change, that I can guarantee you. It defies logic.

Follow your manual.
 

Raduque

Lifer
Aug 22, 2004
13,140
138
106
I changed my oil around 4 or 5 thousand miles ago... and it still looks almost new.
 

LTC8K6

Lifer
Mar 10, 2004
28,520
1,576
126
Wouldn't excessive oil change intervals hurt the CPO program? If the intervals are too long, the CPO engines would be compromised.

Wouldn't oil analysis reveal that 15K is too long, and get BMW in trouble?
 
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Throckmorton

Lifer
Aug 23, 2007
16,829
3
0
Wouldn't excessive oil change intervals hurt the CPO program? If the intervals are too long, the CPO engines would be compromised.

Wouldn't oil analysis reveal that 15K is too long, and get BMW in trouble?

How many miles can a CPO car have? Like 30k max? Not 100k that's for sure. They want you in a new car long before you hit 100k. And most people have no idea what an oil analysis is. Here is one that showed badness at 15k
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=219281
 

LTC8K6

Lifer
Mar 10, 2004
28,520
1,576
126
How many miles can a CPO car have? Like 30k max? Not 100k that's for sure. They want you in a new car long before you hit 100k. And most people have no idea what an oil analysis is. Here is one that showed badness at 15k
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=219281

How could BMW take the risk of specifying a too long OCI?

It makes no sense.

It would only take a few incidents to let the cat out of the bag.

BMW performance car owners could be one group that might have a higher than normal % of people who know about OCI's and oil analysis.

The mere mention of sludge causes a ripple in the engine/time continuum.
 
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Zeze

Lifer
Mar 4, 2011
11,395
1,189
126
I've gone 5000 and even 7000 miles without a single problem.
 

Throckmorton

Lifer
Aug 23, 2007
16,829
3
0
How could BMW take the risk of specifying a too long OCI?

It makes no sense.

It would only take a few incidents to let the cat out of the bag.

BMW performance car owners could be one group that might have a higher than normal % of people who know about OCI's and oil analysis.

The mere mention of sludge causes a ripple in the engine/time continuum.


Really? You think it harms BMW's reputation when a car has sludge at 100k miles and doesn't last to 200k? You think the average BMW buying douchebag who keeps a car 2 years cares about that? The enthusiasts who care about not needlessly destroying cars will just say "Oh BMW you crazy" and change their oil every 3000 or 6000, and buy their cars anyway.
 

LTC8K6

Lifer
Mar 10, 2004
28,520
1,576
126
Really? You think it harms BMW's reputation when a car has sludge at 100k miles and doesn't last to 200k? You think the average BMW buying douchebag who keeps a car 2 years cares about that? The enthusiasts who care about not needlessly destroying cars will just say "Oh BMW you crazy" and change their oil every 3000 or 6000, and buy their cars anyway.

No, I typed all that just to type it... o_O
 

Jimzz

Diamond Member
Oct 23, 2012
4,399
190
106
How could BMW take the risk of specifying a too long OCI?

It makes no sense.

It would only take a few incidents to let the cat out of the bag.

BMW performance car owners could be one group that might have a higher than normal % of people who know about OCI's and oil analysis.

The mere mention of sludge causes a ripple in the engine/time continuum.


Doing 15k is fine for most BMWs and their image as they have larger sumps and also require Syn oil.

If a BMW, or any car for that matter, has issues over 100k then the owner would be blamed. Do you have ALL your service records proving you used BMW approved Sybn oil and never went over milage even once etc...

The reason Toyota had to settle with its sludge issues were many people had sludge issues before 100k and had ALL their maintaince done at a toyota dealer to toyota spec. Even then Totyota fought them but the backlash was enough.