Explain How Oil Can Make An Engine "Smoother"

[Coogles]

I never noticed a difference between oils in my GTP; it's always seen some form of a synthetic 30 weight.

With the Honda, though, I definitely noticed a change. Before it was running bulk dealer conventional oil and a Honda filter; this time I went with Mobil 1 Extended Performance 5w30 and a Mobil 1 filter. The engine is noticeably quieter, especially at 2500+ rpms, and seems to rev more freely as the pedal goes deeper as well.

 

[cp3]

Although, I did run CT Formula 1 in the Saturn a couple times and it always ticed at start up. Never on another oil. Is that subjective?

 

[ryland]

Originally Posted By: rewote500
It's mental. If you put SuperTech in an Ultra bottle people would never know the difference.


Your right you should just use SuperTech lol

 

[ryland]

Originally Posted By: Coogles
I never noticed a difference between oils in my GTP; it's always seen some form of a synthetic 30 weight.

With the Honda, though, I definitely noticed a change. Before it was running bulk dealer conventional oil and a Honda filter; this time I went with Mobil 1 Extended Performance 5w30 and a Mobil 1 filter. The engine is noticeably quieter, especially at 2500+ rpms, and seems to rev more freely as the pedal goes deeper as well.


Im with you, I think its easyer to tell in hondas because of the sustained high rpm's

 

[dnewton3]

I believe you'll see/feel/hear what you want to hear, in general. If you did "blind" double-cross testing, the results would likely be dismal on what people could "hear" via an oil change.

I will admit that large, significant shifts in oil selection might have some effect. Going from a 0w-20 to a 15-40 at start-up might make something a bit noiseier or quieter.

I recall speaking with someone recently who adamantly swore up and down that the "new" synthetic he was using in his motorcycle gave him a percievable 10% more power he could feel through the posterior-o-meter, over his "old" oil. I just had to ask: The "new" oil was T6; the "old" oil was RTS.

Overall, staying within the same grade range, I think the mind satisfies it's own desire.

 

[BobFout]

Originally Posted By: dnewton3
I believe you'll see/feel/hear what you want to hear, in general. If you did "blind" double-cross testing, the results would likely be dismal on what people could "hear" via an oil change.

I will admit that large, significant shifts in oil selection might have some effect. Going from a 0w-20 to a 15-40 at start-up might make something a bit noiseier or quieter.

I recall speaking with someone recently who adamantly swore up and down that the "new" synthetic he was using in his motorcycle gave him a percievable 10% more power he could feel through the butt-o-meter, over his "old" oil. The "new" oil was T6; the "old" oil was RTS.

Overall, staying within the same grade range, I think the mind satisfies it's own desire.


T6 is a bit thinner than RTS at all temps though.

I went from a thicker 5w40 HDEO to a Euro spec xw40 and noticed more "punch" at all temps. Was not expecting to feel any difference.

 

[SLCraig]

Placebo.. I never really notice any change in the way my engine runs really.. I do know based on UOA (or have a good idea) which oil I should be using in my cars, and maybe that's why I say I like the way it runs. I dunno.

Valvoline conventional works great in my '02 Maxima

My Saturn just likes oil period. It doesn't care what it is.

 

[addyguy]

Originally Posted By: cp3
There has to be some difference between different brands and grades or we're all really wasting our time here! Are those differences enough to make a perceptable difference in the feel of an engine? I have "felt" diferences after a change. Seen minor fuel economy differences. Feelings are subjective, but they exist. Fuel mileage is documented but are the differences because of the oil or the stength of the wind that week? As far as the wash and wax, ya everything feels better when it's clean!

As has been said, a lot of syn is used for intervals that could be reached with dino but this makes one "feel" better. Any difference in "feeling" smother on a different oil?


Well put....I agree 100%

 

[Robb235]

Originally Posted By: XS650
I have never noticed it after changing oil in a car, but my motorcycles definitely shifted more smoothly after an oil change, so might be going on.


Definitely true on the motorcycle oil changes. I can always feel the gears shift smoother when ever I change the oil on my R6.

 

[Y_K]

Originally Posted By: Jim Allen
I'd very much like to know the science behind these comments.

The science is rather simple: kinematics and acoustics with a speck of thermodynamics thrown in. Let's say that properties of oil film determines properties of mechanical vibrations and acoustic waves. It can be all mental, all mathematical or both. That's where metrology specialist steps in

 

[Jim Allen]

I have still not heard any SCIENTIFIC explanations. If indeed it runs smoother, I'll try hard to follow along as you tell me why. Prove it with some research, studies or other documentation. I've looked some and not found a shred.

If it's just a "feel" thing, that's fine. Everyone should feel good as often as possible. I always feel good when I know there is new "blood" flowing through the veins of my engine. And yes, I "feel" better when one of my favorite brands is flowing through those veins, but objectively I can see no difference in terms of it being smooth or rough.

I'm either asking for proof that there is some demonstrable, repeatable scientific way to show an engine is smoother with one brand oil or another, or one viscosity or another. If this is true, I really want to know how. In the absence of that proof, it's more intellectually honest for people to admit it's a "feeling" thing (which some/many of you do, granted) and avoid judging or making proclamations based on those feelings alone.

Obviously, people are free to choose their oil based on whatever criteria they wish. It's just that (sometimes very) subjective observations, do not often prove much of anything.

Of course there are difference in brands and types of oils, and how they do what they do, I just don't think (until proven wrong) that they translate into "smooth" or "rough."

Kudos for the civility so far!

 

[Jim Allen]

Originally Posted By: Y_K
Originally Posted By: Jim Allen
I'd very much like to know the science behind these comments.

The science is rather simple: kinematics and acoustics with a speck of thermodynamics thrown in. Let's say that properties of oil film determines properties of mechanical vibrations and acoustic waves. It can be all mental, all mathematical or both. That's where metrology specialist steps in


It's not simple to me. More detail, please!

 

[k24a4]

From, "Auto Repair for Dummies":

The author says, "After years of driving and restoring cars, I've found that clean vehicles run better! After all, humans, plants, and animals respond to being kept clean and cared for, so why shouldn't your car? And if you think that a vehicle is an insensitive object, you haven't been reading this book very carefully."

Now, I don't know if it can be scientifically, objectively, proven that a specific oil can make a car run "smoother", but I would not discount altogether what the author has to say here. Cars are complex machines whose proper functioning relies on many systems running seamlessly together, and all of it is manifest from the minds of brilliant engineers who need the backing of good companies to see their visions brought to fruition. I take car of it; it takes care of me.

As an example of one who may have taken this sentiment too far, I once heard the story of a gentleman who was so enamored with his sports car that one night his wife found him in the garage having his way with the tailpipe.

Not quite sure how the vehicle ran after that.

 

[sbergman27]

People spout absolute nonsense, particularly regarding cars, pet foods, and dietary supplements, all the time. (The dogfood-obsessed are probably the worst.) They post their "experiences" in forums. Other people come along, read it, believe it, pass it on as fact. After reading about it, some try it themselves. Influenced by the subtle but strong influence of the placebo effect, they look at random variations and "see" the same thing in it. In a side-by-side blinded experiment, they'd never be able to tell the difference. But anecdotes are rarely side-by-side or blinded.

Differences between oils are generally not of the "I tried it and..." variety. They are longer term differences. How well does it protect? How long does it protect?

Regarding "My engine runs smoother" claims: IMO, the Emperor has no clothes.

FWIW, I drive quite a bit (16,000 miles since Feb 25) and have had GC 0w30 (a very thick 30wt), Mobil 1 Advanced Fuel Economy 0w30, and Mobil 1 Advanced Fuel Economy 0w20 in my Yaris, all very recently. The engine starts the same and sounds the same with all of them. There is no difference in smoothness (or not) which I can detect. And while the ~0.9 mPa difference in HTHS between the GC and the 0w20 probably does result in an FE boost (likely 1% - 2%) it is below the level that can be pulled out of the "noise" of the average fuel log.

 

[Gary Allan]

Quote:
I have still not heard any SCIENTIFIC explanations.


Someone pulled some links out of their behind a few months back (maybe further back, what seems like a few months can be a good clip longer. Terminator, for me, isn't an "old movie"

). It somewhat validated different basestock compositions as having different harmonic/acoustic characteristics.

Before that/those links, I pretty much attributed it to the placebo effect.

Now here's my own prejudice in the street analysis. I always attributed the "smoother sounding" claims to the placebo effect, but the claims of "noisier" or "less smooth" were totally ignored.

 

[cp3]

Originally Posted By: Gary Allan
Now here's my own prejudice in the street analysis. I always attributed the "smoother sounding" claims to the placebo effect, but the claims of "noisier" or "less smooth" were totally ignored.


At the risk of sounding stupid, again, what's the difference?

 

[Y_K]

Jim, there is no science behind those comments. As is with wine tasting. But if you want a scientific work can be done.
In wine world they trust organoleptic results more although there is a lot of scientific work in wine making. In the motor oil world we have not progressed to oil tasting. Not yet. But it can be done. Science is done by oil companies in our case. What's left to impressionable end user is bitog. As aptly said by someone a few years ago:

'Mobil 1 has the cleanest palate and finishes nicely, but with a slightly soapy aftertaste. Castrol is too high in tannins and always gives me a headache, but it does have a heady, fruity arome and a nice bouquet. Amsoil is by far the best; easy drinking with a complex nutty flavor that hints of chocolate.'

 

[ARCOgraphite]

Didnt mythbuster prove recently a clean car got better fuel mileage?
Mine gets automatically cleaned by rainfall

 

[ARCOgraphite]

Clap your hands in Air at STP, then clap your hands underwater at 3 meters depth. Thats the difference between a 0w-20 and a SAE 50 1/2 way through engine warmup. Now add some fine gradations between the two extremes.

 

[PhillyJoe]

A dirty engine may actually run quieter than a clean engine. Nothing like a 1/2' of sludge on everything to muffle the sounds.