0W-40 in 1970 Cadillac Eldorado

"jim" <"sjedgingN0Sp"@m@mwt,net> wrote in message
.. .
>
>
> Steve wrote:
>>
>> jim wrote:
>>
>> >> By definition a 10w30 and a 30 will be approximately the same
>> >> thickness
>> >> AT OPERATING TEMPERATURE (the rating is made at 100C).
>> >
>> > No your wrong about that. The specification does not require them to be
>> > exactly
>> > the same but that only the difference to be within a specified amount.
>>
>> Hence the word "approximately."
>>
>> At 110C
>> > the difference in viscosity becomes significantly larger. 110C or
>> > higher would
>> > not be an unusual temp for oil in the average car on warm summer day. I
>> > don't
>> > know if that is what krp is trying to say or not. He is correct that
>> > 10w30 will
>> > be thinner than straight 30 in the typical car on a typical summer day.
>> >
>> > -jim
>>
>> By the very factor you pointed out, the actual thickness depends on
>> where both the straight 30 and and the 10w30 fall within the allowable
>> range at the measurement temperature.
>
>
> I was disagreeing with your statement that they would be the same AT
> OPERATING TEMPERATURE. They won't and even at the benchmark temperature
> you can easily tell the difference.


The point I made was this. Using the identical benchmark testing that
Texaco and independent labs used to compare Havoline 10 w 30 to other major
brand 10 w 30 oils that showed a slight advantage to Havoline, when coaxed
to compare Havoline 10 W 30 to Havoline straight 30 - the straight 30 had a
significant advantage. What wasn't much discussed was some testing Shell did
with identical motors with very sensitive temperature sensors. Engines that
were run for thousands of hours. The multiweight oils did not fare well at
all. The "stress" testing is still the benchmark for testing oil. To this
point, the new Castrol Edge is by a significant margin the best performing
oil on today's market. But as I said, do not expect Exxon Mobil to take this
laying down. Like Arnold - they'll be back with an even better oil.

Better living through chemistry.

In article >,
Steve > wrote:
>N8N wrote:
>> On Mar 12, 3:53 pm, Steve > wrote:

>>> Why would you EVER run a 20w50 in anything that doesn't consume oil like
>>> a mosquito fogger?

>> Because that is what the book recommends for the climate I live in?
>> (several old VWs and a Porsche 944)

>OK, air-coolers are a different story. But 20w50 in anything
>water-cooled in the US is just... odd. Maybe something that is so
>worn-out it can't hold oil pressure with anything else...

We had a 1983 Mercury Cougar. We loved the car, but it needed regular
repairs and died at 99,960. (Yes, as a matter of fact, I *did*
contemplate renting a Clydesdale to pull it the other 40 miles . . . but
we were packing for grad school, and I just got rid of it.)

Anyway, it called for 20w50 in its factory handbook. Then again, it
called for three different oils throughout the year in some climates. I
think I got away with only two here in Las Vegas.

hawk

jim wrote:
>
> Steve wrote:
>> jim wrote:
>>
>>>> By definition a 10w30 and a 30 will be approximately the same thickness
>>>> AT OPERATING TEMPERATURE (the rating is made at 100C).
>>> No your wrong about that. The specification does not require them to be exactly
>>> the same but that only the difference to be within a specified amount.
>> Hence the word "approximately."
>>
>> At 110C
>>> the difference in viscosity becomes significantly larger. 110C or higher would
>>> not be an unusual temp for oil in the average car on warm summer day. I don't
>>> know if that is what krp is trying to say or not. He is correct that 10w30 will
>>> be thinner than straight 30 in the typical car on a typical summer day.
>>>
>>> -jim
>> By the very factor you pointed out, the actual thickness depends on
>> where both the straight 30 and and the 10w30 fall within the allowable
>> range at the measurement temperature.
>
>
> I was disagreeing with your statement that they would be the same AT
> OPERATING TEMPERATURE. They won't and even at the benchmark temperature
> you can easily tell the difference.
>
> -jim

That is _simply_ _not_ _true_.

In just about 30 seconds of web searching, I found the spec page for
Royal Purple oils (I'm not promoting RP oils, just found this example
and they are API certified oils unlike some other botique synthetics).

At 100C (the benchmark temperature), their 5w30 oil has a viscosity of
11 centistokes, but their straight SAE 30 is *thinner* at 10.6
centistokes! And their 10w30, while thinner than the 5w30, is still
slightly thicker than the straight 30 weight, at 10.8 centistokes.

Furthermore, the 5w30 has a VI of 157, but the SAE 30 only has a vI of
119, which tells me that you can go WAY above the benchmark temperature
and the 5w30 will remain thicker than the SAE 30.


Here's the link, knock yourself out:
http://royalpurple.com/motor-oil-pp.html

click "Product Sheet" for the PDF.

Steve wrote:
>
> jim wrote:
> >
> > Steve wrote:
> >> jim wrote:
> >>
> >>>> By definition a 10w30 and a 30 will be approximately the same thickness
> >>>> AT OPERATING TEMPERATURE (the rating is made at 100C).
> >>> No your wrong about that. The specification does not require them to be exactly
> >>> the same but that only the difference to be within a specified amount.
> >> Hence the word "approximately."
> >>
> >> At 110C
> >>> the difference in viscosity becomes significantly larger. 110C or higher would
> >>> not be an unusual temp for oil in the average car on warm summer day. I don't
> >>> know if that is what krp is trying to say or not. He is correct that 10w30 will
> >>> be thinner than straight 30 in the typical car on a typical summer day.
> >>>
> >>> -jim
> >> By the very factor you pointed out, the actual thickness depends on
> >> where both the straight 30 and and the 10w30 fall within the allowable
> >> range at the measurement temperature.
> >
> >
> > I was disagreeing with your statement that they would be the same AT
> > OPERATING TEMPERATURE. They won't and even at the benchmark temperature
> > you can easily tell the difference.
> >
> > -jim
>
> That is _simply_ _not_ _true_.

Well no it simply is and was true. Your originally statement that at operating
temperature the viscosity of 10w30 is the same as 30 w is still false. Does that
mean you can't google and find some oil company advertisement. Well of course
you can find advertisements no body said you couldn't.

Your original statement is still false. Most of the 30 weight oil tends to
have higher viscosity than most of the 10w30 at operating temperature. This is
not speaking of some ideal car and oil. It is just how things generally work in
the real world where most of the cars on the road don't use synthetic oil and
many operate with oil temps higher than 100c on hot days.


**There is a allowable range for viscosity at the standardized temps.

**The economics physical realities of producing motor oils for sale puts most of
the 10w30 at the bottom of the allowable viscosity range and the 30w at the top.

**Most engine oil operates at a temperature above 100C on hot summer days

Those facts combined make it generally incorrect to state (as you did) that the
30w and 10w30 oil will have the same viscosity at operating temperature.

-jim







>
> In just about 30 seconds of web searching, I found the spec page for
> Royal Purple oils (I'm not promoting RP oils, just found this example
> and they are API certified oils unlike some other botique synthetics).
>
> At 100C (the benchmark temperature), their 5w30 oil has a viscosity of
> 11 centistokes, but their straight SAE 30 is *thinner* at 10.6
> centistokes! And their 10w30, while thinner than the 5w30, is still
> slightly thicker than the straight 30 weight, at 10.8 centistokes.
>
> Furthermore, the 5w30 has a VI of 157, but the SAE 30 only has a vI of
> 119, which tells me that you can go WAY above the benchmark temperature
> and the 5w30 will remain thicker than the SAE 30.
>
> Here's the link, knock yourself out:
> http://royalpurple.com/motor-oil-pp.html
>
> click "Product Sheet" for the PDF.

jim wrote:
>
> Steve wrote:
>> jim wrote:
>>> Steve wrote:
>>>> jim wrote:
>>>>
>>>>>> By definition a 10w30 and a 30 will be approximately the same thickness
>>>>>> AT OPERATING TEMPERATURE (the rating is made at 100C).
>>>>> No your wrong about that. The specification does not require them to be exactly
>>>>> the same but that only the difference to be within a specified amount.
>>>> Hence the word "approximately."
>>>>
>>>> At 110C
>>>>> the difference in viscosity becomes significantly larger. 110C or higher would
>>>>> not be an unusual temp for oil in the average car on warm summer day. I don't
>>>>> know if that is what krp is trying to say or not. He is correct that 10w30 will
>>>>> be thinner than straight 30 in the typical car on a typical summer day.
>>>>>
>>>>> -jim
>>>> By the very factor you pointed out, the actual thickness depends on
>>>> where both the straight 30 and and the 10w30 fall within the allowable
>>>> range at the measurement temperature.
>>>
>>> I was disagreeing with your statement that they would be the same AT
>>> OPERATING TEMPERATURE. They won't and even at the benchmark temperature
>>> you can easily tell the difference.
>>>
>>> -jim
>> That is _simply_ _not_ _true_.
>
> Well no it simply is and was true. Your originally statement that at operating
> temperature the viscosity of 10w30 is the same as 30 w is still false.

I never actually said that, I said that they would be "approximately"
the same, and that means that the 30 could be either thinner or thicker
than the 10w30 at operating temperature, depending on where operating
temperature falls in relation to the SAE benchmark temperature.

You, however, claimed that (quoting from text reprinted above), "He is
correct that 10w30 will be thinner than straight 30 in the typical car
on a typical summer day," and that is what is categorically false. If
you assume that the 30 and 10w30 are within a small percentage of the
same viscosity at the benchmark temperature, then the 30 will have to
be *thinner* than the 10w30 as you go above the benchmark temperature
because it has a lower viscosity index (in other words, a steeper slope
to its temp. vs. viscosity curve).

That much is just math.

Does that
> mean you can't google and find some oil company advertisement.

Specification sheet, not advertisment. And you can go look up similar
numbers for Pennzoil Platinum, Castrol Syntec, GTX, Edge, Mobil 1, Mobil
conventional, Kendall, Delo, Rotella, etc. etc. Brand doesn't matter.

> Well of course
> you can find advertisements no body said you couldn't.
>
> Your original statement is still false. Most of the 30 weight oil tends to
> have higher viscosity than most of the 10w30 at operating temperature.

See above, this is the part of your argument that is the most incorrect.
It is in fact, generally backwards. You seem to think that 30 weights
will stay thicker at higher temperatures, but the opposite is in fact
true. The simple combination of the fact that the 10w30 and 30 wt. have
to be pretty close in viscosity at the benchmark temperature, and the
fact that the 10w30 has a higher VI *generally* means that the 30 wt.
will be significantly THINNER than the 10w30, not thicker, at
temperatures above the benchmark point. It will be thicker when the
engine is COLDER than the benchmark temperature.

What makes things interesting is that today it is quite possible to
formulate a synthetic oil that meets the requirements for, say, a 10w30
rating and to do it *without* any viscosity index improvers at all.
Synthetic base stocks in both group III+ (eg, Shell XHVI base used in
Rotella and Pennzoil Platinum and similar stock used by Valvoline and
others) and group IV (such as PAOs used by Mobil, Royal Purple, Amsoil,
Shaeffers, etc.) have inherent VIs of 140 and higher now. That means
that the oil company could, if they wanted to, sell it as a 30 weight as
well. And if they do have to add some VIIs to create a multigrade oil
of, say, 5w40, then the amount needed is so extremely small that there's
very minimal benefit, if any, to the single grade oil. Its not like the
old days where making a 10w40 required such a large percentage of VIIs
that they, not the base oil, dominated the deposit formation and
degradation characteristics of the product.

Steve wrote:

> I never actually said that, I said that they would be "approximately"
> the same, and that means that the 30 could be either thinner or thicker
> than the 10w30 at operating temperature, depending on where operating
> temperature falls in relation to the SAE benchmark temperature.

No not approximately the same -they will be noticeably different. It will be
noticeable in oil pressure and in the way that it will drain from the oil pan.

>
> You, however, claimed that (quoting from text reprinted above), "He is
> correct that 10w30 will be thinner than straight 30 in the typical car
> on a typical summer day," and that is what is categorically false.

You believe this because you rely only on glossy brochures for information?

jim wrote:
>
> Steve wrote:
>
>> I never actually said that, I said that they would be "approximately"
>> the same, and that means that the 30 could be either thinner or thicker
>> than the 10w30 at operating temperature, depending on where operating
>> temperature falls in relation to the SAE benchmark temperature.
>
> No not approximately the same -they will be noticeably different. It will be
> noticeable in oil pressure and in the way that it will drain from the oil pan.

So you keep saying. Dig that hole deeper if you want, I'm done.

>
>> You, however, claimed that (quoting from text reprinted above), "He is
>> correct that 10w30 will be thinner than straight 30 in the typical car
>> on a typical summer day," and that is what is categorically false.
>
> You believe this because you rely only on glossy brochures for information?


No, I believe it both because the math predicts it and because
measurements prove it. If you don't believe me, go over to one of the
oil forums and pose the question. Make it simple, ask them if a 30wt
will be thinner or thicker than a 10w30 at temperatures significantly
above 100C.

I'm done beating the dead horse, Jim. You can have the last word now if
it'll make you feel better.

Steve wrote:
>
> jim wrote:
> >
> > Steve wrote:
> >
> >> I never actually said that, I said that they would be "approximately"
> >> the same, and that means that the 30 could be either thinner or thicker
> >> than the 10w30 at operating temperature, depending on where operating
> >> temperature falls in relation to the SAE benchmark temperature.
> >
> > No not approximately the same -they will be noticeably different. It will be
> > noticeable in oil pressure and in the way that it will drain from the oil pan.
>
> So you keep saying. Dig that hole deeper if you want, I'm done.


>
> >
> >> You, however, claimed that (quoting from text reprinted above), "He is
> >> correct that 10w30 will be thinner than straight 30 in the typical car
> >> on a typical summer day," and that is what is categorically false.
> >
> > You believe this because you rely only on glossy brochures for information?
>
> No, I believe it both because the math predicts it

The math is based on a simplistic model that is little more than taking 2 points
and drawing a line thru them. The model is designed to do not much more than
prove a claim to the simple minded and it does that as long as one is willing to
completely ignore the real world.

>and because
> measurements prove it.

What measurements? You have provided only 2 measurements for one particular
brand and that comes with a caveat that you may see some variance from the
measurements in the actual product. You are talking about one particular brand
of synthetic that has a tiny tiny share of the market. That is pretty thin soup
you are calling proof.


-jim


?If you don't believe me, go over to one of the
> oil forums and pose the question. Make it simple, ask them if a 30wt
> will be thinner or thicker than a 10w30 at temperatures significantly
> above 100C.
>
> I'm done beating the dead horse, Jim. You can have the last word now if
> it'll make you feel better.

OK, I swore I wouldn't respond again, but this is just too much.

jim wrote:


>The math is based on a simplistic model that is little more than
taking 2 points
>and drawing a line thru them.


Its not a line, its a curve.


But apart from that the "simplistic model" also happens to be EXACTLY
correct for a Newtonian fluid, which is precisely what defines a
straight-grade oil (no viscosity index improvers are permitted in
straight-grade rated oils). Therefore, the only deviation from the model
in the "real world" will be for the non-Newtonian fluid, which the
multi-grade may or may not be depending on whether it has VII additives
or not. Assuming it does, then it's viscosity will always be higher at
high temperatures and lower at low temperatures than the Newtonian fluid
up to the temperature at which the VIIs disintegrate, but by then both
oils are oxidizing as well! Assuming that it does not have VIIs, then
the "2 point" model is also correct for *it* at the high end (the low
end may still be non-Newtonian because of pour-point depressant
additives) and the two curves will never cross again above the
temperature at which the two fluids have equal viscosity (which in the
example is already BELOW the 100c benchmark).


Duh.



> What measurements? You have provided only 2 measurements for one particular
> brand and that comes with a caveat that you may see some variance from the
> measurements in the actual product. You are talking about one particular brand
> of synthetic that has a tiny tiny share of the market.

Chosen only because they make their data readily available and popped up
first on a Google search. It also happens to be representative of all
PAO-based synthetics in this regard, there's nothing special about it.
In fact in doing a little more research, that brand's multi-grade oils
are apparently considered in the thin side and prone to shearing for
their rating, so in that sense they are a bad case for my argument. Pick
any brand you want, or pick a different brand of straight from
multi-grade. Go ahead. Find a counter-example! Please! Its quite likely
that you can find at least one combination of oils that meet your
criteria, especially since so many of the synthetic single-grades could
easily qualify as multi-grades if dual rating were allowed. I didn't
find such an example, but then I didn't go looking very hard for the
oddball counter-example that may be out there.

> That is pretty thin soup
> you are calling proof.
>

At least I produced actual numbers instead of just waving my hands and
saying the same thing over and over Lloyd Parker style. Or talking about
how you "notice it when it drains out of the pan," which means that its
already well below the 100C benchmark for one thing, and I seriously
question your eyeballs as an accurate measure of viscosity for another.
If my soup is thin, yours isn't even soup yet.

I'm really done this time.

"Steve"wrote:

....non-Newtonian model .... then it's [SIC] viscosity will ...
... when it drains out, its [SIC] below the 100C benchmark..
....Duh...
__________________________________________________ __________________

A long esoteric pedantic treatise is awesome to behold but its
impact is marred by the misuse of language. Some common
writing errors are so glaring they overwhelm the undoubtedly
valuable information being presented. Please have someone
edit for proper English usage then re-post for full credit.

Rodan.