No. What they also cite is that majority of them get blown out the exhaust. So in your case with 120 miles highway driving a week, would be less wear than my 40 miles of stop and go traffic.

It really was no different in the old days- the best way of riding carbon was highway driving.

I think the only info we have now is that keeping the oil clean is the best practice.

I am unsure about annual oil changes. Clearly Jaguar nor others had any clue early chain wear was occurring. When they came up with recommendations. I can even show you on the literature where Jaguar says by using a chain they have eliminated expensive changes. One could sue them for that, belts last longer and are cheaper.

 

Hmm, perhaps I didn't express my question clearly enough.

So let me try it this way: would you expect any difference in oil condition between a car driven on a US coast-to-coast roundtrip of about 6K miles in one month vs. another driven 120 highway miles per week for a year (6240 miles).

 

Good point...opting for the additional TBN testing is a must.

 

Its not you, its me, now I understand better with the stark contrast.
Heck yeah would be my answer. In one scenario you have the ravages of only wear. In the other you have wear + time (oxidation) + a years worth of cold starts.

My comfort zone and opinion; I would not worry about changing oil if I had put 6000 miles in one month. I would worry about changing oil in 6 months with short-trip driving like mine.

 

I'm generally not dense, but I am perplexed as to how the above relates to the GDI/chain wear concern. What you described above has been an internal combustion engine problem for 100 years, and I get that. If anything I'd expect a lot more oil wear in the coast-to-coast car due to cumulative higher temps over longer engine run periods.

However, in earlier posts you presented evidence that the GDI/chain wear issue is related to carbon particles polluting and gas diluting the oil more than in non-GDI engines. Based upon those parameters, I would expect the oil condition in each car in my hypothetical scenario would be nearly identical, since those effects on the oil are mileage/combustion-based.

In other words, two identical cars with equal highway mileage, but differing in terms of cold starts and oil age, might have oil differing on other dimensions, but I don't understand why they would differ with regard to the culprits cited in current theories of GDI-associated chain wear.

 

Not according to the study I posted. Cold engine deposits of carbon nanoparticles was 4times or more higher. Regardless, wear occurs the most during startup, nothing has changed there. In the coast-to-coast driving you eliminate all the other factors that wear an engine aside from carbon nanoparticles, and even that will be significantly lower because of effective exhaust scavenging.

Which may explain why the problem has been more obvious in lower mileage cars than higher. (that is just my experience and not a study)

 

Of course, the alternative hypothesis for seeing it in low mileage cars is that even the fresh oils of today aren't good enough to protect against chain wear in GDIs driven only on very short trips precisely because the majority of engine wear happens on cold starts. It's possible that changing your oil every week still wouldn't protect low mileage cars subjected to that kind of use.

 

This would also mean the problem is widespread and reproducible and recall will follow shortly as all cars, regardless of use, will fail after some number of cold starts.

 

The same would be true with your theory that JLR's oil change interval is crazy, now wouldn't it? I was only going w/ Q&C's statement that he's seen it more often in low mileage cars.

I doubt very seriously that the majority of JLR owners do any more than manufacturer's recommendation, if that.

 

Exactly what SinF said.

If we accept that the chain wear caused solely by abrasive carbon nano-particle; it would be less on a car that had ideal (motorway) miles on it. As indicated in the study. They saw more at lower RPM range and colder engines.

Note they are saying that the soot that gets embedded in oil has a abrasive nature- it gets more embedded in certain conditions than others.

here is a more explanatory study of conditions
http://energy.gov/sites/prod/files/2...lee_2014_o.pdf

 

Absolutely not true. No one has tested changing the oil every week, and subjecting many cars to the same hard cold start, short miles usage over time.

Granted, my illustration was a little silly, but it is clear the problem is just not very well understood, and there is absolutely no evidence YET that shortening the oil change interval will correct the problem.

 

Even if changing your oil every 3 months eliminated the problem, there is no way in this climate of putting the earth first would they recommend it. Just like we will never cut ethanol out of gasoline, even though its destructive to the car.

The whole foundation of all these multi-million dollar studies into GDI wear and nano particle carbon is 'oh snap, we f'ed up, lets find a solution. The solution of going back to what we know works is not acceptable because we want to put lower resource consumption first, including using less motor oil. So more frequent oil change is off the table.

They are not denying there is a huge problem and they are not denying the older technology worked better. They are saying how do we live with this compromise and unfairly pushing the burden on oil companies to find a miracle. The oil companies dare not say, change your oil more often and the problem is solved.

BTW, why do you say fresh oil would not be advantageous? If its not loaded with nano particles, not only will there be less wear, but quicker flow. (I think)

 

I can respect that- its anyone's guess at this moment, including yours. So what you are saying is that although the problem is not very well understood, what is absolutely understood is that shortening oil change interval will have no effect. Is that a fair statement.

 

No, that is not fair statement.

What I said is that no one has any valid scientific evidence to suggest that shortening the oil change interval will have a positive effect toward alleviating the problems you have presented in this thread. Maybe it would, maybe it wouldn't, I'm saying no one knows at this point.

The articles you cited make it clear that current oils are insufficient, and that new blends are necessary. The articles don't say current oils are insufficient when they are dirty, and should be changed more often.

I accept that there is a GDI problem, but I've seen no credible evidence to validate a theory that changing oil more often will solve the problem.

I won't bore you with my academic and scientific credentials, but suffice it to say, I've spent a lifetime practicing and critiquing the scientific method.

 

Sorry to be "that guy", I but changing your oil too early could absolutely harm your engine. Jaguar does not fill each car with this 0w20 stuff and send it to the dealers, that first set of oil is chalk full of additional break in additives required for the car to properly adjust.

So unless you all are supplementing the oil with zinc zddp and some Lucas stabilizer within the first change you have basically accelerated engine wear no less than 40%. Yah!

Oh and if you have a 2016, I you may or may not have over/under filled the engine with oil (jaguar corporate still have not decided on their answer yet officially to my question of how much oil to put in them,.... It's been three weeks......")

Smile!

 

However, would it be a fair hypothesis that if soot loading is an important
contributor, then changing the old oil for new oil more frequently would
result in a lower average soot loaded lubrication regime over time?

It's not a solution for the industry, but rather a mitigating action for the
individual owner.

I have no horse in this race, but the argument is interesting

 

It would be fair to say it is a "promising hypothesis," but the history of science and engineering is littered with debunked promising hypotheses.

 

We are in agreement.

The only scientific evidence we have is that the current scheme has a big problem- there is more harm being done than engines of yore.

 

Yes, and we will see recall and/or recommended service period changed in a couple years once sludge becomes well-known issue. This is lifetime fill transmissions all over. I am really surprised that you do not see it this way. I had to pay for a new transmission, that cost would have purchased couple lifetimes of transmission fluid changes. Original transmission lasted to about 120,000km with no oil changes; replacement used (!) transmission was still going at 400,000km when I gave away the car with bi-annual oil changes.

 

Unlike other theories in this thread, simple oil analysis shows that your theory is not true. They do fill each car with "this stuff and send it to the dealers". Also oil additives like ZDDP might be harmful to your engine, while I use it with flat tappet engines in my classic cars, I wouldn't put it into modern car, especially one that uses 0w20 oil.