Noack Volatility Question

[Camu Mahubah]

Volatization is a term used to describe what happens to a fluid as it is heated to the point it begins to "boil off." Upon reaching a certain temperature, oil will begin to lose some of its lighter weight molecules as they "boil off" and leave heavier weight molecules behind. Not only does this cause higher oil consumption, this process can also cause increased viscosity making the oil more difficult to circulate through the lubrication system.

The ASTM D-5800 (Noack) is a widely accepted method of measuring volatility. Originally developed and used in Europe, the Noack test determines how much weight loss an oil experiences through volatization.

In the Noack test the oil is heated to 150°C for a specified period. The lighter oil fractions will "boil-off," leading eventually to oil consumption, oil thickening and a loss of performance. The test reports results in the percentage, by weight, lost due to "boil-off."

For example, before July 1, 2001, 5w30 motor oil in the United States could lose up to 22 percent of its weight and still be regarded as "passable." Now, with GF-3, the maximum Noack volatility for API licensing is 15 percent. European standards limit high quality oils to a maximum of 13 percent loss.

Question: If one were running a 5w30 GRP III with Noack volatility of 8.9 and oil consumption was around 2 quarts over 4000 miles, would switching to a 10w30 GRP III with a Noack volatility of 6.7 be beneficial? Keep in mind the manufacturer specs 5w30 in this semi-fabulous 2002 Chevrolet Prizm with the 1ZZ-FE. Car has 80000 miles. OCI is 5000 miles.

Question 2: If there are no signs of an oil leak and no actual sightings of blue smoke out the exhaust pipe, where is the oil going? Is the motor similiar to the author of this post as teenager, smoking in hidden alcoves and backalleys, as the author stealthily smoked without parental consent.

The source for the article on Noack Volatility was the ASTM website.

 

[XPR]

Just because you don't see blue smoke doesn't mean its not getting burned. If my engine was down 2 quarts over 4000 miles I would be very concerned. My engine gas over 120k and uses no oil.

 

[buster]

Camu, if you've noticed I always talk about oil consumption and I've always have those two questions. I don't have all the answers but here is what I think:

Noak doesn't always correlate to oil consumption, but in most cases I believe it does. The quality of the VII's and the amount can also make a difference. 10w oils of the same grade are always less volatile. So you might see some "small" reduction.

Oil consumption is not a bad thing but more of an inconvenience. I've know an automotive engineer that said engines that use some oil actually last longer. Their are studies on this I believe.

How the car was broken in also. I now believe in the heavy load/heat cycle break-in method. My Toyota never saw high load at all and that car drank 1q every 3,000 miles. Most Corolla's don't. It could have been avoided, IMO, if I broke it in differently. Car was babied from 9 miles on. However, at 180,000 miles it ran like new. Very impressive little car.

Some cars by nature will just consume oil and fuel dilution is also a major cause of it. RLI oils seem to significantly lower oil consumption after a few OCI.

 

[bruce381]

""Question: If one were running a 5w30 GRP III with Noack volatility of 8.9 and oil consumption was around 2 quarts over 4000 miles, would switching to a 10w30 GRP III with a Noack volatility of 6.7 be beneficial?."""

Yes



""Question 2: If there are no signs of an oil leak and no actual sightings of blue smoke out the exhaust pipe, where is the oil going?""


PVC, EGR and other emmision systems that dump vapours back into air intake.
bruce

 

[Curious Kid]

In AEHaas's post on mineral 0/5w-20 oil being tested in '05 with GF-5 additive chemistry, he made mention in that over the extended OCI of 10k miles, the engines consumed about 3 qts (same engine designs). He states that a lot of it was due in part to the PCV system design.

http://theoildrop.server101.com/forums/s...ge=1#Post986667

Just another factor among many...some additive components have been said to vaporize as well, but none the less part of the whole package.

Take care.

 

[TallPaul]

Quote:

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PVC, EGR and other emmision systems that dump vapours back into air intake.
bruce

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Wow, that could explain why my Aerostar 3.0, which uses a quart every 1300 miles, had a bad ping under heavy acceleration. I retarded the timing 4 degrees. Else I could run high octane. But I wonder if there is something I could do with the PCV system (maybe one of those catch cans or something). Road draft tube is probably out of the question because of EPA/federal law.

 

[Camu Mahubah]

Volatization is a term used to describe what happens to a fluid as it is heated to the point it begins to "boil off." Upon reaching a certain temperature, oil will begin to lose some of its lighter weight molecules as they "boil off" and leave heavier weight molecules behind. Not only does this cause higher oil consumption, this process can also cause increased viscosity making the oil more difficult to circulate through the lubrication system. .

The above statement is one that frightens the author of this post. One does not want to be left with "the heavy" whilst "the thin" hast boiled off. Trying to get 5000 miles outta this oil change has become daunting. Here are some things to consider. After 3000 miles the last UOA showed a TBN of 1.3 with a premium brand conventional 5w30. The motor was switched to a premium synthetic under the assumption that one could extend the drain to 5000 miles as it was obvious the chosen conventional was not up to the task. It has been said that one should expect consumption when switching from conventional to synthetic. This assumption holds true here although the design of this engine is probably more to blame. That and previous owners lack of maintenance leads one to believe extended drains over 5000 miles may not be possible. Without topping off with more oil than the original crankase fill. As of now a four quart fill has been supplemented with two quarts. Would it be advisable to top off the Grp III 5w30 with a Grp III 5w20 to maintain "the thin"? A balance is needed as Winter is fast apon us. Sometime soon the PCV on this motor will be located and replaced. This may solve the riddle of the missing oil or it may lead to more assumpitons. The chum lines are adrift...

Please leave out oil brand recommendations. Oil Theory regarding Noack Volatility and consumption is sought instead.

 

[NissanFan]

I thought that standards D5800 was simulated 250C not 150C, although there is some protocol for 150C and 200C modified?