Freezer test update

Bob Woods · Oct 28, 2003

I put three quarts of oil in my -10F freezer for 24 hours; Walmart Syn blend 5W30, Valvoline max life 5W30 and Chevron synthetic 15w50.

They all poured about the same, but the Walmart blend and Maxlife had a waxey looking film and were cloudy (parrifin?) the chevron was dark but clear.

SPITMAN · Oct 28, 2003

Was it a Woods freezer

KW · Oct 28, 2003

I put some M1 0W40 last week for a couple of days. It was very thick (like syrup not honey) and had white streeks in it.

Bluestream · Oct 28, 2003

This is unrelated to the freezer test, but I recently changed the oil in my boat, and used Wal-Mart Tech 2000 SAE #40. It was cold out, and to get the oil to flow out of the jug, I set it beside the wood stove at my cottage. When I went to pour the oil into the engine, it had turned orange! It scared the **** out of me, but I had to use it, as I had no other oil to install.

[ October 29, 2003, 09:42 AM: Message edited by: Bluestream ]

Dr. T · Oct 29, 2003

At -10F, how can the Chevron 15-50 pour the same as the other 2 5W's? Something's not right with that picture...I've put M-1 15-50 in the freezer..you can bet your bottom dollar it's thick as molasses at that temp. Synth. doesn't mean it's thinner, it just has a lower pour point. But pour points are pretty much useless....ie. all 15W's will be thick as molasses at that cold of a temp. because that is their SAE rating...a 15. Synth's will only give you a slightly added margin of safety...ie. may be slightly more fluid than a conv. at same temp...or not be a block of ice at some temp. where conv. would be.

Robbie Alexander · Oct 29, 2003

quote:

Originally posted by Bluestream:
-*-*-* When I went to pour the oil into the engine, it had turned orange! It scared the **** out of me, but I had to use it, as I had no other oil to install.

Ran into some oil myself that was orange. And another a mix of colors...
MolaKule more or less said that some oils now have these funny dyes in them... maybe this was the case and not the heat.

Bob Woods · Oct 29, 2003

It was very thick (like syrup not honey) and had white streaks in it.

I read somewhere that synthetic oils have some lower grade of oil mixed in as the additive package is bought from some other company and it is made in a carrier oil of who knows what.

medic · Oct 30, 2003

quote:

Originally posted by Dr. T:
At -10F, how can the Chevron 15-50 pour the same as the other 2 5W's? Something's not right with that picture...I've put M-1 15-50 in the freezer..you can bet your bottom dollar it's thick as molasses at that temp. Synth. doesn't mean it's thinner, it just has a lower pour point. But pour points are pretty much useless....ie. all 15W's will be thick as molasses at that cold of a temp. because that is their SAE rating...a 15. Synth's will only give you a slightly added margin of safety...ie. may be slightly more fluid than a conv. at same temp...or not be a block of ice at some temp. where conv. would be.

I disagree. Once again, viscosity has been assumed to mean thickness. These are two totally different things, even more different when you throw synthetics into the mixture.

To help prove my point, think of a hot oil, a 20w-50 will work well for this example. At room tempurature it is a lower viscosity than at 100c (the boiling point of water). However, think of how thin and easily this oil would flow at 100c, but it is acting like a 50 wt inside an engine at that temperature. I always make sure I drain my motorcycle when it is hot because the 20w-50 will flow out alot quicker than if it was cold.

My point in short - the viscosity of a multi-weight oil goes up with temperture increases, but the thickness thins out with temperature increases.

In theory, the chevron 15-50 can pour at the same rate as a 5w-?, but will not protect like a 5w-?? at -10F. I wonder if we can get a lab to check the viscosity of an oil at -10F or lower?

[ October 30, 2003, 11:33 PM: Message edited by: medic ]

Bob Woods · Oct 30, 2003

When I did this test 10 yrs ago I bought a quart of 10w40 of every brand I could find in the local area, Mobil 1 was the only synthetic I could find. Mobil 1 and Phillips Trop Artic were the only ones that would pour out of the bottle. I realize this is a completely BS test, but my concern is, if oil is so thick it won't pour then how do I know it will pump. I remember my Dad talking about draining the oil out at night and taking it in the house and keeping it warm, then pouring it in the motor in the morning, other wise you couldn't crank it, an he was talking about a Model T.

Bluestream · Oct 30, 2003

quote:

Originally posted by Bob Woods:
I remember my Dad talking about draining the oil out at night and taking it in the house and keeping it warm, then pouring it in the motor in the morning, other wise you couldn't crank it, an he was talking about a Model T.

Humm....I am glad we don't have to do that anymore!

dickwells · Oct 30, 2003

Multigrade oil viscosity does not increase with temperature. The grade label means that it is the viscosity of the lower number when cold and of the higher number when hot. Actual measurements with a viscometer show that the viscosity does go down as the oil warms up, just not nearly as much as a normal "linear" fluid. This can be demonstrated by observation of your oil pressure gauge as your engine warms up. Anyone who sees higher oil pressure when the engine is fully warm, please report oil,vehicle, engine, etc.

Bob Woods · Oct 30, 2003

My simple minded way of looking at it is, A 15W50 when hot will perform like a 50W, and when cold it will perform like a 15W.

medic · Oct 31, 2003

quote:

Originally posted by Bob Woods:
My simple minded way of looking at it is, A 15W50 when hot will perform like a 50W, and when cold it will perform like a 15W.

And, back to my point - a 15w-50 when hot is physically thin, and when cold it is phyically thicker.

We all know that a 0 wt. oil is very thin, but a 0w-30 is much thicker at 32F., but they both protect like a 0 wt. oil at 32F.

medic · Oct 31, 2003

quote:

Originally posted by dickwells:
Multigrade oil viscosity does not increase with temperature. The grade label means that it is the viscosity of the lower number when cold and of the higher number when hot. Actual measurements with a viscometer show that the viscosity does go down as the oil warms up, just not nearly as much as a normal "linear" fluid. This can be demonstrated by observation of your oil pressure gauge as your engine warms up. Anyone who sees higher oil pressure when the engine is fully warm, please report oil,vehicle, engine, etc.

If this is the case, why is the viscosity of a multi weight oil lower @ 40C than it is @ 100C? If viscosity went down as the oil warmed up then it would be called a 30w-5.

Drew99GT · Oct 31, 2003

Look at viscosity charts for a particular oil. They are all much much less viscous at 100C. I think the weights of oil, like 5w-30 etc. don't really mean that oil is thinner at colder temps and thicker at hot temps. Think of it as the complete opposite. It's just the way the SAE labels viscosities.

Dr. T · Oct 31, 2003

"...the viscosity of a multi-weight oil goes up with temperture increases, but the thickness thins out with temperature increases."

"If this is the case, why is the viscosity of a multi weight oil lower @ 40C than it is @ 100C? If viscosity went down as the oil warmed up then it would be called a 30w-5."

Are you saying that viscosity and thickness are not the same??? Huh? I think you're confusing a 15-50 with a straight 15 or 50 weight. EVERY fluid will become thinner (less viscous) as the temperature increases...up until it becomes a gas. A multiweight oil will simply be ONE weight at cold temp (measured by a cold cranking number) and another weight when hot (measured at 40 or 100C)...and that's all.

By the same token, oils aren't labelled 30w-5 because the first number "5" is an ARBITRARY number designated to a cold cranking viscosity determined by the SAE/API...no it's actual weight at that temperature. The same with the 30 number.

Hence, it stands that at -10F (-23C) a 15-50 WILL be thicker than ANY 5-30 out there...synthetic or otherwise. In fact, my owner's manual (extreme to some) only lists a 15-50 being appropriate down to -20C. At this point, yes a synthetic 15-50 (eg. M-1) may pour (determined by it's definition: movement on a vertical surface for 5 sec)...however, it WILL be as thick as molasses and thicker than any 5-30 (even conventional) as a 5w has a requried certification of pumping at -30C.

Which could lead one to extrapolate that at -30C, the 5w could be construed as being roughly the same viscosity as a 15w at -20C.

medic · Nov 1, 2003

quote:

Originally posted by Dr. T:
A multiweight oil will simply be ONE weight at cold temp (measured by a cold cranking number) and another weight when hot (measured at 40 or 100C)...and that's all.

So, you do agree that viscosity of a mutil-weight oil does go up as the oil gets up to operating temperatures.

And, the part you can't argue with is that the oil is physically thinner at this temperature than at room temperature. Therefore, viscosity and thickness have nothing to do with each other.

[ November 01, 2003, 08:02 PM: Message edited by: medic ]

Last_Z · Nov 2, 2003

Medic,
I think the mistake you are making is to compare the 15 and the 50 in a 15W-50 weight oil. These two numbers have nothing to do with each other and as Dr. T said, all fluids will thin out as temp. goes up.
At room temperature the 15W side will be much thicker than the 50W side @100*C....that's because those two number are given to an oil using different a temperature scale/range which ONLY applies to respectively.
In other words and simplified....the 15W is given to an oil under very different conditions than when you give the same oil its 50W. 15W is for cold temp ONLY rating and 50W is a hot temp. rating ONLY.
Rick

Drew99GT · Nov 2, 2003

If viscosity is defined as resitance to flow, then oil for sure is tens of times less viscous at operating temperature than when at 0 degrees F. Just because an oil is labelled 5w-30 (example) doesn't mean it thickens up to 30 weight at operating temp. It means it pumps 5w, as defined by the API, and doesn't thin past 30 weight at operating temp. The 5w part of the equation is a relative number the API designates for an oil that pumps at their cold cranking viscosity spec for a multigrade oil of 5w-xx. That measurment is completely diferent than the "metric" they use for determining viscosity at 40 C and 100 C.

Or I could be just plain wrong

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