why to use synthetic

[JonS]

Why would synthetic be good in a cold climate if the pour point and pumping are the same as dino oil? Pennzoil dino has a pour point of -45f with -6600ccs at -30. Their synthetic is the same. Do all 5w-30 oils have to meet the 6600ccs at -30 to be a 5w-30? If so, what is the advantage of synthetic? I should add these reason i am thinking this. Our Checker Auto has Quaker State or Pennz synthetic for $2.00/qrt. I checked the spec sheets and neither of these look any better than their dino oils.

[ August 27, 2002, 09:08 AM: Message edited by: JonS ]

 

[icruse]

Jons,
If you check the Mobil 1 5W30 it is 3,600 @ -30.
The Pennzoil synthetic is a Group 3 oil, not Group 4 (truer synthetic as defined by oil afficianados).
I have never had any problem without having the car plugged in using Mobil 1 in the Minnesota winters.

Steven

 

[Patman]

One other thing to remember when it comes to synthetic vs dino oil performance in the winter, is that even if both oils have the same pour point, the synthetic oil will maintain that pour point better, while the dino oil's pour point will get progressively worse. Although if you're changing it out soon enough anyways, it's probably not much of an issue.

I think the big thing with any oil you choose for winter is that you get one with moly in it, that way the moly provides the secondary layer of protection when that oil is too thick to properly flow through the engine.

 

[kev99sl]

quote:

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Originally posted by JonS:
Why would synthetic be good in a cold climate if the pour point and pumping are the same as dino oil? Pennzoil dino has a pour point of -45f with -6600ccs at -30. Their synthetic is the same. Do all 5w-30 oils have to meet the 6600ccs at -30 to be a 5w-30? If so, what is the advantage of synthetic? I should add these reason i am thinking this. Our Checker Auto has Quaker State or Pennz synthetic for $2.00/qrt. I checked the spec sheets and neither of these look any better than their dino oils.

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I could be completely wrong here (and if I am I'm sure someone will let me know!), but I think the way pour point is determined is completely different from the oil's "pumpability." In other words, I think pour point is defined as the point at which a liquid will stop pouring from an open container. It seems to me that in theory two oils could still pour at -45, but that doesn't necessarily mean that they will both pump as easily through a cold engine. Am I completely off my rocker? That said, synthetics are more than cold temperature protection: they have lower inherent volatility, they generally last longer, stay cleaner, and do a better job of dispersing dirt - and the biggy - they're just more slippery. I will grant you that the shades between the two are less and less distinct, and I will further grant you that the differences aren't wide enough to warrant the price jump between standard and synthetic oils. But I don't think the question is "why stick with synthetics," but rather, "how long will it be until all oils are more-or-less synthetic?" It's coming soon, but I don't think SL is it quite yet.

[ August 27, 2002, 11:54 AM: Message edited by: kev99sl ]

 

[kev99sl]

quote:

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Originally posted by JonS:
And as Bob once said also, just because something is synthetic, does not mean it cleans better. So if the spec sheets are the same between syn and dino(vi, pour point, ccs) they will react the same at say -30c - right? I would think the only benifit for syn is extended drains - right?

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And just because the information on the spec sheets is the same, that doesn't mean that the oils are identical. Spec sheets don't address issues like cleanliness and dispersant properties. You're lucky if they include volatility figures. And for the information they do provide, did they use the same tests to come up with those figures? Spec sheets also only tell you how the oil will behave right out of the bottle, not how long it will maintain those properties, and under what conditions.

 

[kev99sl]

quote:

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Originally posted by Patman:
Synthetics really aren't more slippery, Bob has mentioned that to us many times. The base oil has nothing to do with an oil's "slipperiness"

If two oils have identical additive packages, and are the same viscosity, but one has a synthetic base and the other a petroleum base, they will both be just as slippery as one another.

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Yeah I know. I'm still not sure I really agree with that assertion.

 

[Patman]

The one thing is though, most synthetics do end up being more slippery after all, because if you look at their virgin analysis results, they do have more antiwear additives in almost all cases compared to their dino oil counterpart. But the point is, they are not more slippery due to the base oil being used, but because of the extra additives. A dino oil or blend with a better additive package is going to be more slippery than a low quality synthetic with an inferior additive package.

 

[widman]

Very interesting discussion, especially since I just came from a meeting with a company that insists that it is a waste to put anything more than a cheap dino oil in the engines because company policy is to change out the fleet every 4 years. At no point is a better resale value attributed to the maintenance dept. Only out-of-pocket expenses are evaluated in their performance.

 

[MolaKule]

If you're trading trucks every four years, and the bottom line is all that matters, then I am sure that works, Widman.

Most of us here are looking for longevity in engines coupled with performance.

All tests I have seen show PAO/Ester or Ester base fluids having lower overall coefficients of friction than do dino fluids. ZDDP for example, is an anti-oxidant, an anti-wear, and friction modifier (multifunctional-additive) that lowers the coefficient of friction below that of the base fluid.

No matter what base fluid you use, you will always want to lower the coefficient of friction to the lowest possible value.

 

[jason07-1zzfe]

Molakule, according to TORCO, ZDDP INCREASES friction...
http://www.torcousa.com/tech_info/tech/lube_engineering.pdf

 

[MolaKule]

Interesting reading, but apparently the author hasn't read the same SAE and STLE papers that I have. I see two errors:

1. ZDDP does act as a friction modifier and anti-wear agent, (2nd page). Any chemical that turns into hard deposits reduces friction. Deposit control is allieved by other additives.
2. Rings do not rub on dry iron. (fourth page). It's mixed lubrication and the oil film is approx. 1um.

His MPZ sounds like Schaeffer's #132 to me. (Page 4)

 

[MolaKule]

Any chemical that turns into hard deposits reduces friction. Deposit control is allieved by other additives.

Should have read:

Any chemical that turns into hard deposits increases friction. Deposit control is allieved by other additives.

 

[Patman]

Synthetics really aren't more slippery, Bob has mentioned that to us many times. The base oil has nothing to do with an oil's "slipperiness"

If two oils have identical additive packages, and are the same viscosity, but one has a synthetic base and the other a petroleum base, they will both be just as slippery as one another.

 

[icruse]

quote:

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Originally posted by kev99sl:
But I don't think the question is "why stick with synthetics," but rather, "how long will it be until all oils are more-or-less synthetic?" It's coming soon, but I don't think SL is it quite yet.[/QB]

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kev,
I think you're right on here. It is obvious that the trend in better oils to meet the more stringent and better specifications, synthetics are becoming ever more populous and popular because of their advantages.

Steven

 

[JonS]

And as Bob once said also, just because something is synthetic, does not mean it cleans better. So if the spec sheets are the same between syn and dino(vi, pour point, ccs) they will react the same at say -30c - right? I would think the only benifit for syn is extended drains - right?

 

[MolaKule]

On page 9 under summary and conclusions the author says: "In order to save energy and convert that extra horsepower anti-wear additives that contain zinc will have to replaced with an additive that has better anti-friction properties..."

So the author admits that ZDDP is an anti-friction additive and that new anti-friction, anti-wear additive need to be developed. So I agree with this last statement. The author is simply not being consistent; on page 2 he says ZDDP is a stiction chemical while on page 9 he says it's an anti-friction additive. He can't have it both ways.

In addition, I would have modified the above sentence to read: "In order to save energy and convert that extra horsepower [to torque] anti-wear additives, that contain zinc, will have to replaced with an additive that has better anti-friction properties..."

Well we have those additives in the form of Moly and Antimony, phosphate esters, and other metal dithiocarbamates. They are not all that new, by the way.

 

[TooSlick]

JonS,

There are some very average quality synthetic lubes out on the market - in particular the Group III stuff. You need to look both at the basestock blend used and the robustness of the additive chemisty, ie the levels of anti-wear and detergent/dispersant additives. I've been following this industry for 24 years and Mobil 1 is the only other synthetic that I consistently recommend. I am sure there are other good oils out there, but I haven't seen the same track record for those.

Its not that synthetics necessary clean better, however they are generally more resistent to heat and oxidation, so they degrade less than average quality petroleum oils and leave fewer sludge/varnish/carbon deposits.

TooSlick

 

[Patman]

Mark, I don't believe Mobil 1 is quite that good. When I bought my 95 Formula used, with 56k on it, the engine had quite a noisy valvetrain. Mobil 1 was put in the car right away, and even 5 or 6000 miles later, the valvetrain was noisy. I put in a GM additive which helped clean the sticky valvetrain, and the noise got considerably quieter. A short while later I added Auto-rx and the valvetrain now sounds totally normal for an LT1, maybe even a tad quieter than the typical LT1! So Mobil 1 alone wasn't enough to clean this engine out.
I do believe Mobil 1 helps keep engines very clean (I've seen it on my own engines) however once an engine is dirty, it needs more help than Mobil 1 can give.

[ September 01, 2002, 03:22 PM: Message edited by: Patman ]

 

[TooSlick]

The cleaning properties of synthetic lubes comes primarily from the organic ester portion of the basestock (typically 10%-15%). So it can take 10,000-15,000 miles to clean out an engine with heavy sludge/varnish/carbon deposits. I always use the Amsoil engine flush on any engine with over 50k miles that I am conventing to Amsoil. If you don't do this and try to run a long drain interval, the first batch of synthetic can get extremely contaminated after 6000-8000 miles.

For heavily sludged up engines, I believe the Auto RX is probably an even better way to go. I have been testing this stuff and have been impressed with how well it cleans. It will also reduce seal leakage, based on the limited testing I have done. Finally, it appears to have no effect on the carrier oil.

TooSlick

 

[Mark in NY]

As long as you mentioned cleaning power of synthetics let me give you my experiences.
I have had customers come to me over the years with noisy lifters. The Sentra stands out as a car with this oil related problem more than others. More than once I have changed the oil using Mobil 1 in the specified grade 5-30, driven the car through the RPM range (spirited driving?) and have had the noise completely disappear in 15 minutes. For years I have considered Mobil 1 the best engine flush around.