Viscosity Breakdown in Oils

[Odyssey USA]

One thing I learned in 30 years of engineering is that a good portion of designs of complex machines will not perform in service as perfectly as intended. Some fail completely to perform as intended, some get it done for a while, but not as long as expected. All kinds of unexpected performance failures occur. I made a career out of understanding chronic failures of critical airplane systems and communicating to regulators what happened, why, and what we were going to do to fix it. That interview with the Mopar engineer highlights the reality. He couldn't know what the in-service experience would bring. Failed cams and rockers, blown head gaskets, and endless oil filter housing issues.

Agreed. I noticed he confirmed the timing chains and oil pressure actuated valvetrain had conflicting interests…. but they let it ride. lol

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[JesseT]

Nothing is more economically important to an automaker than drivetrain longevity...

You're talking about the same company that says the transmission fluid is a "lifetime fluid" right?

 

[Oletimer]

I would believe he mischaracterized it to you. He may have been told to make a choice to choose a design that had less predicted life, but the reason for it was not specifically to shorten life, but to reduce costs.

Another thing is I've been driving rams awhile. I run the heck out of them .
Never had engine trouble till my 2018 , and my 2020

Your talking about the same company that says the transmission fluid is a "lifetime fluid" right?

Technically no, I guess that would have been Chrysler fiat era. But same results, shorter life of products.

 

[TheRaven]

It's great you have such blind faith in these big corporations. One of us is gullable.
Either me for believing him or you for believing they wouldn't.

Your friend was messing with you. I'm an engineer, we don't "design things to fail" at a certain point. Everything is designed with a life span in mind...but that doesn't mean it's "designed to fail". It's spec'd to ensure that it lasts a given amount of time. For me, it's MTBF, but it's the same concept.

All of this argument is silly - changing your oil viscosity by 5-20 points is not going to make a material difference in the longevity of your motor. Period. I've said this countless times - just use what helps you sleep at night, but don't fool yourself into thinking you're fixing anything or preventing anything.

 

[Jeep Wick]

Nothing is more economically important to an automaker than drivetrain longevity. So no, they are not going to knowingly "sacrifice statistical reductions in engine life for fuel economy". Especially when we're talking about a significant reduction in engine life for what amounts to statistically insignificant increase in efficiency. They aren't going to knowingly risk having engines blowing up at 80k miles just to get a 0.01mpg increase.

I'm sorry but this is hilarious. They are in the business to make money, not sell you a vehicle that will last forever. Bean counters have more influence than the engineers. Toyotas from the 90s are outlasting anything being built today. Plastic cooling systems and thin oils are the Achilles heel of modern engines. The fundamental design has not really changed but now everyone runs 0w Vs 10w40 of old. Kia and Hyundai famously have engines that can't be rebuilt, "throwaway" motors with warehouses full of replacements. This has been the business trend.

 

[TheRaven]

I'm sorry but this is hilarious. They are in the business to make money, not sell you a vehicle that will last forever. Bean counters have more influence than the engineers. Toyotas from the 90s are outlasting anything being built today. Plastic cooling systems and thin oils are the Achilles heel of modern engines. The fundamental design has not really changed but now everyone runs 0w Vs 10w40 of old. Kia and Hyundai famously have engines that can't be rebuilt, "throwaway" motors with warehouses full of replacements. This has been the business trend.

I'm glad you were entertained, but you have no idea what you're talking about. "Thin oils" are not the problem with modern vehicles.

 

[roaniecowpony]

I'm just one of those guys that believes film strength is the primary protection from wear on our engine moving parts, and that film strength correlates with viscosity strongly. So, all other boundary protection additive characteristics of the oil being equal, I like the idea of a higher viscosity than 0w20 provides.

 

[Jeep Wick]

I'm glad you were entertained, but you have no idea what you're talking about. "Thin oils" are not the problem with modern vehicles.

Agree to disagree. We sure see a lot of wear and lubrication failures. Remember when Castrol would drain engines and run them to prove they had better protection? Mobil 1 would take apart motors to show you how they prevented wear? If additives and different formulas can have such a dramatic effect, surely viscosity makes a difference. @roaniecowpony is sharing how the new oils break down, I would not disregard this. Manufacturers make sacrifices to hit targets, this is in every industry.

 

[TheRaven]

Agree to disagree.

Deal.

 

[NWJeepr]

I hear you. And you could well be right. But I repeated it as told to me.
But he is the one that said about 25,000 miles per year and 5 year notes .
It added credibility to story in my eyes. But I am not a eye witness to this.
I still believe it ! Lol

Since he told you....checks watch.... Nine years ago...

You'd think there would be a lot more 5.7 failures or parts specific to the 5.7 failing since they're apparently only designed to last 5 years/ 125k.

If your friend is the Ma Teresa of engineering that you say he is, where's the proof in the pudding? We should have plenty of evidence by now.

I think some of us are left wondering what level this guy was at, too. Those kinds of statements can carry serious liability for a company, so someone in "the know" with these things isn't likely to tell someone about intentional failure design to someone else who repeats those lines in a public forum. Not if they're paid well and/or aren't willing to risk personal exposure.... I'm thinking this is a pile of horsefeathers.

 

[dstevens]

Since this is the internet, I must voice an opinion not matter what knowledge I can bring onto the subject.

Any Pentastar engineer has no credibility. Every other manufacturer with a chain driven overhead valve dual VVT head manages to get their engine to last 250,000 miles. A Pentastar is on - what the 13th? - revision of the followers and they still regularly wipe the cam. A single stage thermostat ensures that the engine runs hotter than it needs to. Every time you start the engine from overnight you get to hear the valve run without oil. No other engine I've ever driven does this. The oil cooler seals fail. Cylinder heads fail. I'd just love to see the raw warranty data compared with other manufacturers.

So bad that I got the small 4 cylinder overly complex Italian rattle box this time around.

 

[swampflyer]

I didn't mean to confuse you. I'm using thicker oil. I know this much; 0w20 isn't preventing rocker/cam failures from happening. YMMV. I like overkill too.

As you can see I live in the free state of Florida and it gets hot here. What do you think of maybe 5w30 instead of 0w20. You really didn’t confuse me what I was trying to say was it’s just a dilemma to try and figure out what is better for your engine. I’m always open for educated common sense remedies for the jeepin community and your experience is noteworthy.

 

[azwjowner]

Every time you start the engine from overnight you get to hear the valve run without oil. No other engine I've ever driven does this.

I'm not sure if this is better or worse, perhaps worse (because it means inconsistent production quality), but my Pentastar doesn't rattle on startup -- even after two weeks sitting.

 

[roaniecowpony]

As you can see I live in the free state of Florida and it gets hot here. What do you think of maybe 5w30 instead of 0w20. You really didn’t confuse me what I was trying to say was it’s just a dilemma to try and figure out what is better for your engine. I’m always open for educated common sense remedies for the jeepin community and your experience is noteworthy.

For a 30 grade, I would suggest the M1 ESP 0w30 rather than a random 5w30. It is near the upper end of the bracket for 30 grade viscosity. You can get it at Walmart and O'Reilleys or was it Autozone?

 

[Odyssey USA]

I'm just one of those guys that believes film strength is the primary protection from wear on our engine moving parts, and that film strength correlates with viscosity strongly. So, all other boundary protection additive characteristics of the oil being equal, I like the idea of a higher viscosity than 0w20 provides.

Same. Mitigate metal to metal rather than depend so much on the additive pack.

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