Extended OCI's

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From what I'm seeing here, extended oil change intervals are done to reduce the time and cost of maintenance on a vehicle but we don't have enough information on the long term consequences for those that keep their vehicles beyond the warranty. The examples here might be from people that really care for their vehicles but that does not represent the majority.

A UOA is telling us about the oil but there's still the question about the actual condition of the engine.

Since most people don't keep cars that long the longer OCI makes sense. When there's doubt you just trade.

What prompted me to ask was what I saw today. A BMW that ran dealer oil and religiously followed the BMW intervals. A couple of UOA's look good, no problems noted. At 200K the engine is junk. It just barley failed the California smog test. It looks pretty clean inside, no sludge but the crank has egg shaped journals, compression rings perfect, oil control rings failing, the camshafts are gone and so are a lot of the other bits and pieces that would really run up the overhaul bill. In simple terms, this engine is not a candidate for a rebuild. It was economical to maintain but not to rebuild. So the owner got a vehicle that was not expensive to maintain. If the second owner would have received this vehicle without the tear down the ownership might have been expensive. The car is being parted out.

So it appears that the extended OCI's achieved their purpose.
 
The "BMW intervals" are not extended, they are the factory ones; It is more an indictment of their testing and engineering prowess than extended intervals.

Plenty of appliance vehicles running > 1.5x to 2x factory OCI with no such failures.
 
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Oil is cheap. Engine rebuilds aren't.

The average dino oil change costs $15 in oil and $5 for a filter, or $25 in oil if you use a synthetic like Mobil 1.

I'd much rather pay an extra $30 every 5,000 miles than to run 10,000 mile OCIs and risk increased engine wear down the road. $30 is less than the cost of 1 tank of gas!

Regardless of what your opinion is on extended OCIs, the one fact which we all know is that a 10,000 mile OCI will not produce lower wear numbers than a 5,000 mile OCI. At best, a 10,000 mile OCI will produce wear numbers that equal a 5,000 mile OCI, but not better. At worst, a 10,000 mile OCI may produce significantly increased wear, and that wear may not show up until past 100k miles, at which point it's already too late.
 
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Originally Posted By: AccordK24
...the one fact which we all know is that a 10,000 mile OCI will not produce lower wear numbers than a 5,000 mile OCI. At best, a 10,000 mile OCI will produce wear numbers that equal a 5,000 mile OCI, but not better. At worst, a 10,000 mile OCI may produce significantly increased wear, and that wear may not show up until past 100k miles, at which point it's already too late.
How do we know that? What objective information do you have to share that proves this? The 10K plus UOAs that I have seen do produce less wear metals per mile than 5K ones do or at best it is statistical noise between the 5K and 10K+ UOAs.
 
Originally Posted By: sicko
I don't think anything can be concluded from this isolated incident.


...and extended intervals have only proven to reduce immediate maintenance costs. The future has yet to be determined.
 
Originally Posted By: OneEyeJack
...and extended intervals have only proven to reduce immediate maintenance costs. The future has yet to be determined.
Extended intervals have been around for many years, do we not have enough information to know if they work or not?
 
BMW doesn't make good cars though.

Honda and Toyota have intervals approaching or exceeding 10k and run with no problems to 300k and more.

Even 20+ years ago on SG/SH dino the factory OCI's were 7500 miles, with Honda only recommending changing the oil filter every *other* OCI. And today's SN oil is many times better than the group I SG/SH from the 90s.
 
So what is the BMW factory OCI, 12k miles? Seems reasonable for highway driving, but maybe not for 5 miles at a time in a city.
In my climate atleast, there is most likely no point in trying to get an engine to last for much more than 200k miles anyways, the body will most likely be shot at 12-15 years .
 
Originally Posted By: AccordK24
Oil is cheap. Engine rebuilds aren't.

The average dino oil change costs $15 in oil and $5 for a filter, or $25 in oil if you use a synthetic like Mobil 1.

I'd much rather pay an extra $30 every 5,000 miles than to run 10,000 mile OCIs and risk increased engine wear down the road. $30 is less than the cost of 1 tank of gas!

Regardless of what your opinion is on extended OCIs, the one fact which we all know is that a 10,000 mile OCI will not produce lower wear numbers than a 5,000 mile OCI. At best, a 10,000 mile OCI will produce wear numbers that equal a 5,000 mile OCI, but not better. At worst, a 10,000 mile OCI may produce significantly increased wear, and that wear may not show up until past 100k miles, at which point it's already too late.


Most of what you said is wrong. I personally have been doing 10K OCIs since 1978. None of my engines have never shown any sign of wear. Now a quality oil should be used. Some of my engines have ran well in excess of 200K and one was 354K when sold and ran fine. Oil used: M1
 
I have a 01 Silverado with over 350k miles that gets 1 oil change per 7500 miles (conventional oil) I will gladly take pictures to confirm this if anyone has a doubt.

If convention 7500 OCI can take a engine to 350k miles on original engine (320k miles original transmission) I don't feel its hard to go 10k-15k on synthetic oil.
 
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Wear is not linear. The evidence suggests that slightly more wear occurs with fresh oil and decreases over the life span of the oil, as long as the additives are not fully consumed. In addition, more wear occurs on cold starts, especially in the winter time, than when the engine has warmed and is at operating temperature. Using the same logic, far less wear occurs during highway driving than city so a 'fixed' OCI is only a guideline.

If you think about it logically - for an average consumer driving , say 10K/yr:

Winter: lots of cold weather starts and short trips (commuting, school, driving rather than walking or biking)
Spring: warmer starts, mix of short and long trips
Summer: more longer trips, no school

Given this usage pattern, far more of the wear would occur in the winter than summer. If you change the oil, say, in fall and winter, most of the wear would take place in the winter. You might come close to exhausting the oil additives in the winter oil but use only 50% of the summer oil additives. An extended life oil would take advantage of your annual usage pattern and smooth out the additive consumption.

Using an oil designed for extended intervals along with a high quality filter, along with a moderate driving style (and confirmed by analysis) can produce lower wear per mile at a lower cost and greater environmental benefit. On my Accord, UOA indicates wear of about 1/2 of the average using M1-EP after 13K. I see no reason not to use an extended OCI after the warranty period.

In addition, premium oils like M1 or PP often have larger rebates, bring their prices in line with dino. Some also are thinner to save a bit of fuel. In my case, I save in lower costs and labor, but more importantly, I do not waste 2 hours extra going to my dealer, waiting for the car, and returning.
 
211kphh.jpg
 
Interesting OP. A lot of German cars do not get the proper spec oil, but you said this one had been dealer serviced so you would think it did.
 
I've got 456k between a 98m3 and a 96 Tacoma 3.4 with 10k OCI for each. No brained. Less work I have to do on a car the better. Back in the 70s I' d do 2k OCI's with carbs and such. No more.
 
Originally Posted By: slacktide_bitog
BMW doesn't make good cars though.

Honda and Toyota have intervals approaching or exceeding 10k and run with no problems to 300k and more.

Even 20+ years ago on SG/SH dino the factory OCI's were 7500 miles, with Honda only recommending changing the oil filter every *other* OCI. And today's SN oil is many times better than the group I SG/SH from the 90s.

My brother hit 550,000km on BMW 525d (E60) in Europe. So please man.....
 
BMWs, at least the 80s-2000, are good cars. They are not Toyotas, and when you are driving one you are glad that they are not toyotas. I own both.
 
Originally Posted By: oliveoil
BMWs, at least the 80s-2000, are good cars. They are not Toyotas, and when you are driving one you are glad that they are not toyotas. I own both.

Of course they are good cars. And of course they are not driving like Toyota, which like you said, is a very good thing.
Most of the ruined BMW's I saw were ones that were maintained like Toyotas. Usually driven by people that do not have a clue about what is under the hood, no idea about in-line six's and cold starts etc. They start the engine, floor it down and that is it.
 
Not enough info! ? It seems that too many new members with old ideas are now the voice of BITOG, and that makes me sad...
 
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