Maybe Helix has higher Sheer Stress factor?

The only thing that would make the oil loss less if it were less volatile i.e. a heavier oil, it will have nothing to do with Sheer Stress Factor. Oil sheer is mostly a thing of the past with synthetic lubricants as they have an inheremtly high viscosity index in the first place unlike purely mineral based oils where it was necessay to add a polymer thickener (known as a viscosity index improver) to the oil so as to obtain both the low temperature (winter grading) and the high temperature requirement as measured by an oils viscosity at 100 deg C.

The only thing that would make the oil loss less if it were less volatile i.e. a heavier oil, it will have nothing to do with Sheer Stress Factor. Oil sheer is mostly a thing of the past with synthetic lubricants as they have an inheremtly high viscosity index in the first place unlike purely mineral based oils where it was necessay to add a polymer thickener (known as a viscosity index improver) to the oil so as to obtain both the low temperature (winter grading) and the high temperature requirement as measured by an oils viscosity at 100 deg C.

I think you almost there, read this stickies, should help

http://www.briskoda.net/forums/index.php?/topic/90661-16-important-OIL-questions-answered!

I quote from the Oil sticky thread.....

14) Why do some engines consume oil? Is this a problem?

Large air-cooled engines or classics with wide piston clearances, or very highly stressed liquid-cooled engines which flex under load, or which use ultra-light pistons with the minimum number of rings are likely to be oil users. There is little that can be done about it. Unfortunately, burnt oil tends to leave hard deposits in the combustion chambers which can initiate pre-ignition, so more frequent top overhauls are usually necessary.

Occasionally, touring engines will use oil for no apparent reason. This is often due to the oil level rising in the crankcase due to air retention, leading to oil loss through the breather. The answer is to move to a lighter grade of oil to improve air release.

I think you almost there, read this stickies, should help

http://www.briskoda.net/forums/index.php?/topic/90661-16-important-OIL-questions-answered!

I showed you where to find the pinned article the other day.

I showed you where to find the pinned article the other day.

Very informative too, I have just read it thanks.

Very informative too, I have just read it thanks.

James, it is a good piece. I wont say that i agree totally with all of the content but then we are all entitled to our own opinions.

I showed you where to find the pinned article the other day.

LOL, I am getting old

Still, Shear Index or whatever it's called is the most important factor, all other comparable, in oil spec as it specifies the ability to "hold the oil film" if it makes sense. Viscosity has nothing to do with it really as it is a measure of oil flow ratio under certain temperatures, now measured for 150C, not 100C. Viscosity Index defines oil behavior under different temps making synth nicely SAE multigrade without the need to add Black Death additives to the otherwise mineral oil. THat is my opinion based on reading SAE literature and other

Actually, the upper SAE grading i.e. 30 is measured at 100deg C and it is the Kinematic Viscosity. The High Temperature High Shear viscostiy that you are talking about is the one measured at 150 deg C and is the rotational viscosity and is directly proportional to the amount of drag induced on a rotor against the stator in the apparatus when it is rotated at a set speed. The reverse of this is the Cold Crank Simulator to determine the winter grading as per SAE J300. Both sets of aparatus can be obtained from a company near Manchester called Ravenfield and i used to have both of them in my lab along with a whole host of other test equipement. As to the SAE literature also check out ACEA and dont forget the API as well, you'll probably find some good stuff there. Alternatively i'll look you out a couple of good text books that i have back in the office that I have used and were particulary helpful when i did my Masters in Lubricant and Hydraulic Engineering. Shear stress is not related to any of the testing above and does not demonstrate Sheer Stability. As to the discussion about VI, what i was trying to demonstrate here is that due to either the refinery process i.e. level of hydrotreatment, or by the fact of using synthetically prepared hydrocarbons, you can obtain base oils that have a very high viscosity index, especially when compared to straight run mineral oil base stocks and as such do not require the use of a Viscosity Index Improver. VI improvers by there very nature are long chain polymeric molecules which are not shear stable. They are added to straight run mineral base stocks to improve high temperature viscosity whilst having little or no effect on low temperature viscometrics. The issue being that during the oils life it is the polymeric VI improver that shears (think of it like chopping up spaghetti) and as such its thickening ability will decrease.

What would be interesting to look at is the Noack results for both the Helix and Edge products as these will provide an indication of the oils volatility, and thus the amount of loss that can be attributed to the heating of the oil. This was what i ultimately meant the other day.

*tips his hat bowing* I stand schooled and corrected!

Thank you for your post well informative and should make a sticky!

What I thought I was ranting about was the ability of an oil to maintain the "film cover" at high temps, thus dealing the rings against the bore better, and the more viscous the oil the better it does it - I could hear the ringing but wasn't sure which church tower was it coming from .

It is a specialist field and I suppose I was a bit arrogant thinking that after reading for few hours articles on the web I knew it all ...

Hey no problem, I've only been at this for 26 years and there is a hell of a lot of stuff i don't know:)

A tricky question then for you Jerry, which oil do you use in your vRS?

Have you by any chance dealt with fluorinert type of oils? http://solutions.3m.com/wps/portal/3M/en_US/ElectronicsChemicals/Home/Products/ElectronicLiquids/?WT.mc_id=Electronics_Redirect&WT.tsrc=Redirect

I am looking for one with the best heat capacity and low viscosity i.e. as close to water as possible...

The answer to the tricky question is Castrol Edge 5W/30. However, when i get the car back I will probably change that to something else. I'll need to have a look around and consider what is best. However, technically, provided it has passed the VW 502 requirement any should be suitable. One thing i may do though is go for a slightly heavier product and move to a 5W/40. As well as the VW credentials i will also ensure that i go for the highest API S classification.

As to Fluorinert fluids, I do not have a great deal of experience on these apart from knowing they are very expensive. I believe we have used them as a heat sink fluid in some forms of electrical equipment but that is about it. Note with these they are also sold by the kilo and because they have a very high density (IRC about 1.5 kg/l) one kilo is equivalent to about 600 ml. Off hand i can't even remember who we buy them from, but then we do procure some 800 different petroleum products from various suppliers so it is difficult to remember them all. You will also need to consider whether the fluid will actually be compatible with the equipment you want to use it in so consider what the current fluid is and its properties (in particular seal swell) and whether the Fluorinert product exhibits similar properties towards the materials it will come in contact with or whether they will behave differently. What do want to use it in?

Just looked at the 3M page and now recall where we use at least one of those products. They are very expensive:)

is there not too much over analysis here?

my garage serviced my car for 30k with syntium 5000xs 5w30 which is normally used by BMW dealers to service their diesels! lol...

and mine doesn't use oil.... I would say as long as it conforms to VW's 502 standard its ok.....

I just looked at the User manual and it reads VW 504 00 for flexible service intervals and VW 502 00 - what is the biggest difference as i understand 504 is more stringent than "old" 502 ?

Sharkrider, probably it is overanalysed but hey, we enjoy it

Sharkrider, you are quite correct. Provided it has passed the VW 502 sequence of testing, the oil should be fully suitable for the 1.4 TFSI. However, mine has lived on a diet of Edge 5W/30 and after 28000 miles is now in my local dealers having its head removed. during its life it has had three services (the last one literally before the misfire started), been subjected to the oil consumption test (determined as being 482mls/1000 kms) and an additional 12 litres of oil. All i am considering doing is moving to a different product post completion of any rectification work, that meets as a minimum the VW 502 requirement, has the highest API classification as possible as this will indicate that this is one of the newest formulations possible and probably move to an alternative brand. Unfrotunately not all oils are created equal even though they may pass as a minimum a set of sequence tests.

As to the other stuff about oil testing and the like, you are quite correct and that was down to my big headedness, and is complete overkill for this forum, or at least, for this thread and would probably of been dealt with better in a PM and i duly appologise for my boastfulness. I was out of line and this is not a cursory thumbing my nose at you, i am being serious.

lol.. I wasn't criticising guys you crack on! I was just giving a simplistic view

I strongly suspect that all this oil burning problem is to do with the engine designers trying to reduce fuel consumption by reducing friction by fitting piston rings with lower tension so less friction against the cylinder walls.

I strongly suspect that all this oil burning problem is to do with the engine designers trying to reduce fuel consumption by reducing friction by fitting piston rings with lower tension so less friction against the cylinder walls.

Sry, don't get it.. lower tension piston rings?

I was asking about difference between VW502.00 & VW504.00 after reading this

http://www.oilspecifications.org/articles/vw_motor_oil_specifications_explained.php

And it looks like VW502.00 is way worse than VW504.00... What is your opinion on this one Jerry?

It would be lots simpler if VAG admitted to a Manufacturing or Component problem at some point or some place.

Too many engines with no problems for it to be a design fault.

Just an explanation as to why or what they are modifying or having to modify on a small percentage of the engines they manufactured would be a simple thing to understand.

Which engines they agree to Replace or rebuild and exactly why this has become required.

ie

was there a Manufacturing or Component error.

Not Rocket Science, just Mechanical Engineering & customer service.

Someone with a current problem needs to ask Skoda UK or VAG in writing or through a Solicitor really.

george

http://www.oilspecifications.org/oiltool/oiltool.php - interesting tool. Not sure how current...

Just had a call from my dealer

Car was in for service today and we asked them,again, to look into the excessive fuel consumption

Anyway.....They have read a bulletin from Skoda

Parts for the manifold are on order that will solve the oil consumption issue

Anyone else know what these parts may me?..the girl in reception had no idea

I am inclined to beleive that this will still be the 'breather' fix still.

It will be good to be proved wrong and find out they are coming up with another solution for those having problems.

I think untill a Service Manager or Senior Technician can explain the actual problem and the fix, we are still in the dark.

?? Any chance please that you can Email Skoda UK and ask for a comprehensive & detailed explanation?

george

Itake it you meant oil. My car was in yesterday an had the breather mod an ecu upate. Just been on the telephone to skoda who have asked me to run it for 3 weeks. Also if i give them the receipts for the 8 litres of oil used then they will refund me.

Just had a call from my dealer

Car was in for service today and we asked them,again, to look into the excessive fuel consumption

Anyway.....They have read a bulletin from Skoda

Parts for the manifold are on order that will solve the oil consumption issue

Anyone else know what these parts may me?..the girl in reception had no idea

Did you have to have the oil consumption test carried out by the dealer (where they remove and weigh oil, run car for so many miles, remove and weigh oil again) before they would order the parts?