Are extended OCI bad for engine performance?

[CharlieBauer]

Everyone knows that Blackstone believes you can run TBN to 1 and that often wear metals seem OK at low TBN numbers.

Yet elsewhere there is differing advice eg change oil when TBN is below 3 from PQIA, change when TAN crosses TBN, change when TBN is 35% of virgin TBN.

In light of that, I've always been skeptical of Blackstone's recommendation.

Various other observations and comments from knowledgeable people got me wondering if Euro oil intervals are too long.

I just changed oil after 2 years which is allowed for exactly the same vehicle in Europe. I used the same approved Euro oil and in CA, we also have low sulphur gasoline. Yet the vehicle feels noticeably improved with fresh oil. Oil analysis indicated that going 2 years would not be a problem and mileage was only 5.5k miles over 2 years.

It reminded me of the findings in this video. Ignore the mistakes in some of the explaining, but see the before and after oil change results in 0-100 runs.

 

[bbhero]

This is not a question meaning to be a pain in the you where to you. But what do you notice in improved performance?? I don't disagree at all with your observation. I'm just curious as to what you noticed different.

 

[FCD]

Some people "feel" their car runs better after an oil change, most likely just the placebo effect?

 

[Lubener]

At 5500 slow miles, the oil is likely to be somewhat dirty. The way I see it, the PCV system draws up crankcase vapors and is reintroduced during combustion and analyzed by the O2 sensor. If these vapors are very "polluted", the exhaust gases out of the engine will be negatively affected and by the signal voltage out of the O2 sensor for those conditions, the ECU will make adjustments to compensate for those readings. So I can believe your thoughts on a performance improvement with the new oil.

 

[CharlieBauer]

Originally Posted By: bbhero
This is not a question meaning to be a pain in the you where to you. But what do you notice in improved performance?? I don't disagree at all with your observation. I'm just curious as to what you noticed different.


No problem. It was mainly smoother.

But in any case, if you haven't watched the video, go to 4 minutes to see the before and after comparison.

 

[bbhero]

Well I agree with your observation here as well. I will say that on my Ford Fusion and Altima 3.5 I don't notice quite as big a difference as when I had a 95 Nissan Sentra. The old Sentra ran smoother and definitely has better pick up after a oil change was done. On my last two newer cars I have to say that difference is really not has noticeable. My lady's 98 Camry is similar to my old Sentra. It sounds much quieter and has a better pick up feel as well after a oil change.

 

[BrocLuno]

Originally Posted By: FordCapriDriver
Some people "feel" their car runs better after an oil change, most likely just the placebo effect?


Not...

One of the things we do to help older motors get by SMOG Inspections is to change the oil and filter. Often before the change there can be some some slight smoking at idle with old oil (these are engines over 200,000). May be valve guides, may be ring pak related. Who knows w/o a tear-down... Fresh oil it is diminished.

Will that help it run better? Prolly. It certainly helps it idle better.

The old oil is sheared down and thinner. The new oil is not

Same oil, no brand switching, no viscosity increase.

 

[mjoekingz28]

I couldnt even watch a minute of that video.

But to your question,

In this day in age, many thing seem to last longer all the while requiring less care. After lots of overmaintaining my equipment, I have finally relaxed a little and find you should probably not venture far from guidelines.

Like a lawnmower I inherited....it ran great and started on first or second pull probably every time. Then I found a manual for it- changed the oil, filter, put a prefilter on it, new spark plug, you name it. It then turned into a poor running machine. So, you kind of need to do what you feel is best and that can take experience, studying, training, and alot of help from those smarter than yourself.

I think changing Mobil1 EP every 1000 miles Will Hurt your car! It may sometimes seem too much of a good thing is a great thing, but things generally have a sweet spot. The latest and greatest isnt always that. Sometimes it is done right and with good driving habits and a responsible maintenance routine, I feel your car will break-in and wear in and be a better car. If you overmaintain it, it is like having a deathgrip on the handlebars of a motorcycle and not letting it follow the road grooves a little bit- you are fighting this wear and something has to give....

On the other hand, if you run it ragged, dont warm it up, drive erratically, skip maintenance and cheap out on repairs, then you may just have a heap in a few years. So, what you have done seems great. A slight gain in quality when you fix something is nice. Like the oil has begun to degrade but is still performing reasonably well and all is well. Like shifting a racecar. If you shift too early you wont hit the powerband, just right and the power should taper off slightly letting you know it is time for the next gear, but too late and you hit the limiter, cause damage, or toast it!

 

[SonofJoe]

In concept, there's nothing wrong with extended OCIs. You only have to look at what happens on commercial trucks, where 50,000+ mile OCIs are common, to conclude it must be technically possible.

There no absolute answer to the question because max OCI depends not only in the oil itself but how you drive, the prevailing climate, your vehicle, it's age, the relative size of the sump, etc , etc.

However if you have full synthetic oil with a very low Noack with a goodly amount of add pack (and not a lot of VII) and you live in a temperate climate and drive gently with a decent percentage of highway running, then I wouldn't worry too much about running out to a 12,000 mile oil drain. You would probably be good to go to 15,000 miles but there comes a point where the balance of risk to reward says, just change the oil.

 

[UltrafanUK]

A TBN of only 1 is OK for just one OCI, BUT if you want to do such long OCI's it makes real sense to use an idle flush additive just before an oil & filter just to make sure the block is clean, otherwise you will get a long term build up of sludge to start with and top end varnish deposits later.

Oddly enough changing the oil too often can cause more wear, as the first 1000 miles with a new oil is when most of the wear occurs.

 

[Doc8404]

Originally Posted By: UltrafanUK
.

Oddly enough changing the oil too often can cause more wear, as the first 1000 miles with a new oil is when most of the wear occurs.


Where's this study?

 

[FCD]

Originally Posted By: rsylvstr
Originally Posted By: UltrafanUK
.

Oddly enough changing the oil too often can cause more wear, as the first 1000 miles with a new oil is when most of the wear occurs.


Where's this study?

I have read a study where they found additives like zddp take a thousand miles or so while to start working properly , oil filters also work best after they have seen some use.

 

[Alex_V]

Originally Posted By: UltrafanUK
Oddly enough changing the oil too often can cause more wear, as the first 1000 miles with a new oil is when most of the wear occurs.


While I understand (some of) the logic behind this, I'm not sure how it explains dad's '97 Suburban - Vortec 350 has seen Maxlife OC's every 2,500-3000 miles (even I would have been running it 5K) since 170,000 miles, and I swear it runs just as well with 420,000 miles on the same untouched engine. The Vortec 350 is a darn good engine, but not at the top of the "easiest to hit 400K" list.

 

[BigCahuna]

It sure seems like another "My opinion is better then your opinion" video. One labs opinion vs another's. Oil companies make money when they sell you oil, so some want you to change your oil more then needed. While others offer a product they claim will last up to 3 times as long. Lab tests show after 10-15k miles the oil is still has service life remaining.I guess it all depends on YOUR particular motor and the condition it is in while the oil is being used. Vary's from vehicle to vehicle, and owner to owner. A street driven car driven whats considered "Normally" oil will test differently then a car that's only driven on a track. If there's anything that might help reduce particulate count in used oil, that would have to be a new oil filter or one with a a smaller micron count to trap the metal pieces each time the oil gets filtered thru it.If you believe everything in the posted video about wear particles wearing out your motor, there wouldn't be so many high mileage vehicles around. Think about that.,,

 

[UltrafanUK]

Not seen one but if you look at a UOA series with the same & filters, but different OCI's, the shorter intervals normally show a higher Fe per mile figure. How much higher depends upon the average trip length. It's much more critical if you short trip.
The detergents in the new oil are a tad too effective and tend to damage the anti wear layer until a new one can be baked on, which takes time. That AW layer is critical during cold starts, so the effect of changing the oil too often is less of a factor if you do not short trip.

An oil filter that contains carboard gets a lot better at stopping smaller particles when dirty, same for the air filter. A synthetic oil filter is different as the new and pre change efficiency ratings are almost the same.
Typical figures for a traditional oil filter might be 95% when new and 99.5% when real dirty. So a clean filter lets past 5% and an almost blocked one lets past only 0.5%, so the dirty filter is around 10 times better at stopping 20 micron particles.
I can never understand why the OEM's don't fit differential pressure monitors for both oil and air filters, so you can judge when to change them. Big trucks have them!

 

[demarpaint]

Extended OCIs are bad when people do them blindly because someone said X oil can go 5,000 miles, and a synthetic oil can easily go 10K miles no matter what. Following blanket statements can get you in trouble. If you plan on doing extended OCI's get a UOA or two to back them up.

 

[UltrafanUK]

In general terms older engines were not close tollerance and used far better bearings, also driver style makes a huge difference to engine life. It's best to judge the age of an engine on a combination of factors like how old it is, how many hours it has been run and the number of stop start cycles. Mobil are good at demonstrating that a standard Merc engine can do 500K km on M1 0w40 before failing, but then don't say how the test was done, as it's a non stop one at moderate revs in a clean lab. The clean air is important as the limiting factor would often be the air filter.

Blackstone Lab have a UOA for a Nissan truck on record that was for an OCI of 165K miles and that was in the big sky country (Montana) where the air is very clean, as are the roads. The engine was OK and the filters had not blocked, BUT it was a very rare case as the oil should have been much thicker than it was, BUT a bad injector had caused enough fuel contamination to keep it in limits.

 

[UltrafanUK]

Originally Posted By: demarpaint
Extended OCIs are bad when people do them blindly because someone said X oil can go 5,000 miles, and a synthetic oil can easily go 10K miles no matter what. Following blanket statements can get you in trouble. If you plan on doing extended OCI's get a UOA or two to back them up.


Very true!

 

[4WD]

Mobil's proof of performance is done by a taxi company ...

 

[Kuato]

Interesting TV show segment; too bad their analysis did not include TBN and TAN of both samples - that would have been more conclusive. Guess they had to fit in some commercials and dumb it down for the normal audience.

IME, I had a 90hp vehicle in the 80s and was using Castrol 10w40. I religiously kept track of MPG and took a lot of long trips along the same route through West Virginia.

I was using the factory recommended 3000 mile guideline at the time. The car was noticeably down on power and MPG near the end of the OCI, which jumped back to normal with fresh oil. Not able to afford synthetics back then I tried VWB, which did not cause any loss of power or MPG.

So I agree with their conclusion; it may not be a huge difference, but it's there. A better quality oil will last longer, and I wonder what they were using in their VW.