Engine startup wear understanding

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Hello all,

I know there is a lot of oil company marketing regarding engine startup wear and how to reduce it, etc. Motor oils have various anti-wear additives that are more effective at different temperature ranges.

So, tell me if I am wrong, but it seems most of the wear occurs in that middle temperature range when additive effectiveness (cold anti-wear) drops off and (hot anti-wear) kicks in as the oil reaches full temperature.

Is that the general understanding on this subject? Good day all.
 
There are Anti-wear and anti-friction chemistry for Cold start, mid-range, and hot engine regimes.

Cold start wear is way overblown.
 
Most of the wear from start up occurs during the moments between when the engine starts and when it builds oil pressure. The concept behind lower viscosity oils is that they flow much better in cold environments, so the engine bearings will have oil quicker.
 
I never took an engine apart and found dry bearings, I would think the residual oil protects well enough til it get oil pressure.
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Originally Posted By: jeepman3071
Most of the wear from start up occurs during the moments between when the engine starts and when it builds oil pressure. The concept behind lower viscosity oils is that they flow much better in cold environments, so the engine bearings will have oil quicker.

Not if the papers and references posted on here are true. It's what seems like would be the case but apparently is not.
 
Perhaps engine startup wear could also be contributed to human driving behavior. I think we all have seen people get into their cars and tear off. Appreciate the input.
 
Very True KrisZ. Mine is more of an interest than a worry for me personally. Just curious as I appreciate people and knowledge here.
 
Originally Posted By: Trav
I never took an engine apart and found dry bearings, I would think the residual oil protects well enough til it get oil pressure.
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Not only that, the AW and FM additives don't separate from the oil film just because the oil is cold.
 
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I think bore and piston wear are the main issues in a healthy engine. The pistons and bores are cold so haven't expanded to their properly warmed up shape, also cold oil might not be getting thrown under the pistons as it would when hot.

Claud.
 
Originally Posted By: KrisZ
Probably more so than the all knowing engineers that get cited here all the time.


No engineers of any kind cited in this thread so far. In fact no citations at all.
 
Startup wear is highest whenever the engine is cold, but i don't overthink it, i don't warm up any of my cars at all and right now all three of my cars have over 100k miles, driving normally is what warms them up the quickest.
 
Originally Posted By: Char Baby
I used to be concerned about startup wear until I joined BITOG. Now, I don't overthink it!


Same here, unfortunately I feel some are the opposite. They read a bunch of posts about dry starts, how anything but 0wXX oils will cause extra wear, and they start worrying.

Without a bit of technical knowledge or experience it's quite easy to start believing claims that only sound valid in the most simplistic terms.
 
I can't find the reference right now, but we had some professional papers that show cold start wear occurs mainly in the ring band on the cylinder walls. SAE 30 straight grades was found to be the best at preventing it because it had no viscosity modifiers (VM's) and viscosity index improvers (VII's), which have no real lubricity value ...

As the oils have gotten better of late with chemistries that yield wider viscosity spreads w/o VM's and/or VII's, they are yielding results closer to the SAE 30 residual film strength on cold surfaces. So they can rightly claim to reduce cold start wear by some factor (against traditional multi-grades). And we get the benefit of less viscosity and easier starts in really cold conditions.

All engines are wet inside all the time. Residual oil films protect on initial start. Bearings are protected by pumped oil in a few seconds. But they could run longer on residual oil. Cylinder walls are oiled by sling oil off the crankshaft and the oil control rings scrape most of that off with each stroke. So they need new oil soon. But cold thick oil does not sling as well (say SAE 30 at near freezing), so this area suffers. Add to that the enriched fuel/air mixture which dilutes and washes oil off the upper cylinder walls, and you have wear.

We have all now seen modern EFI engines with 200,000 miles with the cylinder hone pattern still showing. That is proof that much better fuel control (compared to carburation) and modern oils have gone along way toward curing this issue withing the bounds of the average car or light truck. Most will rust and fail before engine wear is an issue ...

Big rigs now routinely go over a 1,000,000 miles between major overhauls. We are living in the golden age of lubricated internal combustion engines. Most all is well
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However, what will happen when we move ever closer to bio-derived renewable fuels like E85 for the average drive, I do not know. Alcohol can create a whole new round of chemistries that can damage oil and engines ...
 
I have seen large chillers , prior and during start up . Of course , they are not operating in COLD weather .

First of all , they all ( I think ) have crankcase / oil sump electric heaters . Next , the electric oil pump comes one as part of the start up sequence , and operated by what I am guessing is a timer . Then , the chiller finally starts .

Got me to thinking . What if your car engine had an electric 12 VDC oil pump which came on , say , 30 seconds ( or until an oil sensor showed positive oil pressure ) . Then the starter circuit was enabled .

Would not be unlike energizing the glow plugs on a diesel engine .
 
Originally Posted By: mbacfp
Is Castrol's whole Magnatic stuff mostly marketing?


Yes, and the marketing seems to work well too.
 
Originally Posted By: FordCapriDriver
Startup wear is highest whenever the engine is cold, but i don't overthink it, i don't warm up any of my cars at all and right now all three of my cars have over 100k miles, driving normally is what warms them up the quickest.


With the temperature you have there on the islands I wouldn't worry either, but in the northern states & canada warm up is something think about
 
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