Seriously. At the bottom over every BITOG rabbit hole is a used Tesla some guy just traded in for a gasser who just found this forum and who just posted his first "what oil" thread.
Please Explain to me how changing the oil, increases wear for the next 1,000 miles
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Seriously. At the bottom over every BITOG rabbit hole is a used Tesla some guy just traded in for a gasser who just found this forum and who just posted his first "what oil" thread.
The idea that UOA results reflect wear rates is entirely in error. Or even that we can tell what component produced the Fe, for example, was it cylinder, cam, follower, chain, oil pump, etc. Actual wear rates must be physically measured. To infer the rate of wear after an oil change by taking an oil sample is insanity itself. This was and still is very well known in the oil industry. I was involved in turbine engine oil testing and grease testing. We pulled innumerable samples to ensure there was no disaster, but when it came to wear rates, complete disassembly and study via the scanning electron microscope was king.
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It's not accurate to use UOA's to determine this unless you drain every last drop of used oil out of the engine during your oil change, and that's impossible without a tear down.
We expect about 0ppm iron immediately on fresh oil, right? Then after 5000 miles we might see (say) 20 ppm. We "curve fit" that on a linear equation and expect to see:
0ppm at 0 miles
4ppm at 1000 miles
8ppm at 2000 miles
12ppm at 3000 miles
16ppm at 4000 miles
20ppm at 5000 miles
But we're not starting with fresh oil, and that old oil still has some iron left in it. So really it may actually be this:
2ppm at 0 miles
6ppm at 1000 miles
etc
So it looks like you're getting a spike at 1000 miles and the "rate of increase" is going down as we sample out further in time, but that could be due in part to the dirty oil not starting at 0ppm.
We expect about 0ppm iron immediately on fresh oil, right? Then after 5000 miles we might see (say) 20 ppm. We "curve fit" that on a linear equation and expect to see:
0ppm at 0 miles
4ppm at 1000 miles
8ppm at 2000 miles
12ppm at 3000 miles
16ppm at 4000 miles
20ppm at 5000 miles
But we're not starting with fresh oil, and that old oil still has some iron left in it. So really it may actually be this:
2ppm at 0 miles
6ppm at 1000 miles
etc
So it looks like you're getting a spike at 1000 miles and the "rate of increase" is going down as we sample out further in time, but that could be due in part to the dirty oil not starting at 0ppm.
This. $25 UOA can watch for trends and possible disasters, but not wear rates on individual or combined components.
I find it ironic some folks go both ways, when really both short and long OCI, you really don't know. Sure change your oil early, but don't think you are magically extending engine life and come off as a superior in the brain section. When it remains quite unknown.
I think this is the main point. Other factors might contribute very slightly, like competing additives packages, tribofilms etc but I think 99% of this phenomenon is just the leftover contaminations affecting initial ppm.
Racing oil has been typically formulated with a low ppm overbase detergent vs a pass car lubricant . I don't think this became de rigueur by some whim or feminine feeling.
you are not looking at molecules but elements in this basic analysis
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There's a chemical change as the AW and FM chemistries establish their tribofilms during run-in and simultaneously the DI package uses up some of its initial "bite". Heat and pressure have an effect on the AW and FM additives, their chemistries and their behaviours, so my understanding is that it's that same run-in process after an oil change where the new AW and FM chemistries go through that "activation" and the DI package is at its most potent, that some of the existing tribofilms are reduced/removed/compromised and then quickly repaired/replaced as that process completes.
Patman
Staff member
So one takeaway I’m getting right now that I never really considered before is that it might be beneficial after an oil change if you take a bit of a longer drive on the highway where the engine isn’t being stressed too much and it allows the protective barrier to establish itself again. Or at the very least, don’t drive the car too hard in the first little while immediately after a change.
Also don't short trip it, so it never gets hot.
One thing about where I live that is great, is my vehicles have a few kms of back roads to warm up everything like diffs, transmission, engine etc. Then the road comes to a hwy where the speed limit is 90 kms/hr so it requires a hwy stint to go anywhere.
Real mechanics, excellent mechanics, would laugh at a lot of things that have posted through the years.
Patman
Staff member
For me, because I live in an apartment I have to drive 15 minutes to my Dad’s place to change my oil so after that change I am always giving it a good run, especially since I often do other errands anyway while I’m out. I don’t short trip my cars really. My girlfriend lives 50 miles away and my part time job as a tour guide in Niagara Falls is 80 miles away. And especially with the Corvette, I will often fill my day with a nice 2-3 hour pleasure drive
It's been covered pretty well, but the theory is based on a study that found a spike in wear rates initially after an oil change. This was not measured with a UOA but rather detailed profiles of the metal surface and tribofilm thickness. ZDDP is an acidic ester. ZDDP tribofilms are thus also slightly acidic. Detergents are acid neutralizers. It doesn't take a rocket scientist to see how they hate each other. Detergents, especially when fresh, will overpower ZDDP until sufficient heat and load activates the ZDDP. Thus, chemical stripping of the anti-wear films occur until that point.
This is also the basis behind not using common shelf oils for break-in oil. Even with additional ZDDP added, with its reactivity subdued by high amounts of detergents, ZDDP won't be as effective until it reaches sufficient heat and load. This is a big part of why dedicated break-in oils exist, to make ZDDP the star of the show and get everything else out of its way.
That said, this is not something anyone should lose any sleep over. In the grand scheme of things, the effect this has on overall wear throughout the life of the engine is very small to moot. It's an interesting phenomenon (at least to me it is) but irrelevant to most.
Don't take oil advice from mechanics. Most of them don't even know what the "W" in a multi-grade stands for, much less the complex reaction of conflicting chemistry in elastohydrodynamic lubrication regimes. It's like asking a McDonalds fry cook how Gordon Ramsey achieves the perfect sear on a ribeye.
This is also the basis behind not using common shelf oils for break-in oil. Even with additional ZDDP added, with its reactivity subdued by high amounts of detergents, ZDDP won't be as effective until it reaches sufficient heat and load. This is a big part of why dedicated break-in oils exist, to make ZDDP the star of the show and get everything else out of its way.
That said, this is not something anyone should lose any sleep over. In the grand scheme of things, the effect this has on overall wear throughout the life of the engine is very small to moot. It's an interesting phenomenon (at least to me it is) but irrelevant to most.
Don't take oil advice from mechanics. Most of them don't even know what the "W" in a multi-grade stands for, much less the complex reaction of conflicting chemistry in elastohydrodynamic lubrication regimes. It's like asking a McDonalds fry cook how Gordon Ramsey achieves the perfect sear on a ribeye.
Excellent post!
The way some people rev a car from overnight cold has a far greater impact on wear than any 1,000 mile OCI.
Scott
Scott
Patman
Staff member
That is true. I have always said that the way you drive your car in the time period from the cold start until it’s fully up to temperature will play a HUGE role in its longevity. I have always driven my cars gently when they are warming up and I have never had an engine die on me (or consume any serious amount of oil either)
When I hear someone do that I cringe.
Even revving it up right after a warm start.
And then we have the must rev it hard, and shut it off crowd.
I hate that my F150 on a cold start wants to idle at 1400 rpm, not 1000 max. And I sit in it, and wait for idle to drop below 1000 rpm before I put it in gear. When i get to my destination, i let it idle for 20 seconds or so before I shut it off, and its not a turbo that has to spool down.
My big trucks I start, watch the oil pressure come up on the gauge, then get out and do my walk around. Now its had 5 minutes idling I kick it up to hi idle, which is about 800 to 900 rpm depending on the truck. I fill in the info on my ELD tablet, and put it on the passenger seat, once I see the water temp gauge show over 50 C I will move it gently, but no high rpm or much throttle. The 4.5 kms to the hwy from my house is fairly flat, and maximum 50 kms/hr, so I drive it gently to the hwy. Everything is pretty well warmed up by the time I reach the hwy. When I get to wherever it was I'm going, if shutting the truck off, I turn the fan on manually, and let it idle about 2 minutes in winter, or 5 minutes in summer.
When the high idle comes down from 1400 rpm, that's the car telling you it's ready to drive. No reason to idle for 20 seconds when you stop. That's just wasting fuel, however small.
No need to wait until 50°C to start driving. You're just wasting fuel idling that long and will take longer to reach that temp than it would just driving it. There's a fleet in Alaska (using HPL) that regularly cranks up in -30°C to -45°C temps. They start it, log the hours, put it in gear, and away they go. No difference in wear rates vs letting it idle to warm up.
Your vehicles love you!
A confirmation of your tactics... During the hot summer months after driving one of our German cars I open the hoods when they get parked in the garage. I even put a fan in front of the grill. I think this is a good way of preserving underhood wiring, vacuum tubing, and coolant hoses.
The notoriously leak prone cam cover gaskets on our BMWs - the E90 finally started leaking at 115K, which is well beyond the point that most start leaking. And my bought new by me 25 year old E46 with 96K miles on it has ZERO seepage on its cam cover gasket. I directly attribute this to opening the hood and using a fan when I park them after they've been driven. The reduction in heat soak has to be significant.
Scott
Edit: I haven't driven the E46 much the last two years. I change the oil every January. The last two oil changes were done with under 700 miles on the oil. The horror!
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