what temp does your oil get up to?

[ArthurPE]

What are those temps in the international unit of centigrade?

Kelvin...I'm guessing the F indicates something...

Which has exactly what to do with the oils lubricating properties?

as flashpoint decreases, so does lubrication qualities, the volitility increases...common knowledge...if the oil hits hot metal and evaporates can't lube very well can it?

Not quite. Yes, the temperature IS taken from the sump - but sump oil is categorically not the hottest location for the oil. Localised oil temperatures will be noticeably hotter on the small-ish volumes of oil which is sprayed onto the underside of the pistons. And the same can be said for the localised oil surrounding the valve stems of the exhaust valves.

yes, not quite, exactly...the temp is measured in the sump (which is a physical average), pre-cooling, the actual oil that is pumped to lubricate is cooler...not sure what your point is

And although we arn't graced with turbos on the B7 RS4 - turbo bearings are arguably by far the hottest localised area for oil.
what has this got to do with an RS4? or its normal operating temp...and sometimes that isn't the case, as in a water cooled turbo...I would bet the underside of the pistons are hotter...


Rubish. For a modern automotive specific engine oil - its optimum operating temperature is in excess of 80-85 deg C. If the oil drops below 60deg C, it noticeably looses some of its lubricating abilites.

wrong, again, I won't call it 'rubbish', just lack of knowledge... oil should operate around 160 to 200, avg 180F (82C)...so if it in the sump at 200-220, guess what a 20-40 differential does?


an additional HTHS - or 'High Temperature, High Shear' test - so won't be an issue. And then contamination - if your oil contains enough 'contaminents' to lessen the lubricating qualities of the oil, then either there is a problem with filtration (no element, damaged filter medium, or incorrect filter), or the oil is massively beyond its sheduled oil change interval.

still a fact, whether you agree or not...you think oil temp is the only factor in it's performance? what if it had sand in it? lol

[PetrolDave]

I saw 109 Celsius on Thursday after a spirited drive, and it was only 12 Celsius air temperature.

[Teutonic_Tamer]

What are those temps in the international unit of centigrade?

Kelvin...I'm guessing the F indicates something...

Nope - you stated Farenheight (sp?) - being as the planet beyond the USA uses Centigrade (OK - correct term Celcius) - I, and I guess others have difficulty in understanding deg F figures.

Which has exactly what to do with the oils lubricating properties?

as flashpoint decreases, so does lubrication qualities, the volitility increases...common knowledge...if the oil hits hot metal and evaporates can't lube very well can it?

Sorry - but that is utter nonsence. I kindly ask you too correctly look up the definition of "flashpoint". Flashpoint specifically referrs to vapours - ie, a substance who's physical state is a GAS. Automotive engines soley rely on LIQUID state lubricants.

"Flashpoint", "volatility", and "vapour point" are three very differing fluid properties - and you seem to be confusing the attributes of one property with another.

Finally; care to enlighten us on exactly what 'hot' part of an engine can vapourise a high quality oil?

Not quite. Yes, the temperature IS taken from the sump - but sump oil is categorically not the hottest location for the oil. Localised oil temperatures will be noticeably hotter on the small-ish volumes of oil which is sprayed onto the underside of the pistons. And the same can be said for the localised oil surrounding the valve stems of the exhaust valves.

yes, not quite, exactly...the temp is measured in the sump (which is a physical average), pre-cooling, the actual oil that is pumped to lubricate is cooler...not sure what your point is

My point is that the oil gets considerably hotter than the figure shown in the DIS. So, going by your logic, and from an earlier misleading post about oil braking down around 120deg C - then we'd be digging out lumps of coal from our sumps, rather than draining a liquid.

And although we arn't graced with turbos on the B7 RS4 - turbo bearings are arguably by far the hottest localised area for oil.

what has this got to do with an RS4? or its normal operating temp...and sometimes that isn't the case, as in a water cooled turbo...I would bet the underside of the pistons are hotter...

My point on the turbos is that the very same oil that is specified for our B7 RS4s is exactly the same oil specified in other very high performance Audis with turbos.

And your comment on turbos being water cooled - well some are - but some are categorically not. And let's be quite clear - a water cooled turbo uses a water jacket on the outer edges of the bearing housings. The hottest part of a turbo - the exhaust gas turbine is categorically not water cooled - the primary way the exhaust turbine is cooled is via the oil for the bearings.

It is a bit of a moot point weather the underside of a piston, or a turbo bearing is the 'hottest'. The crucial issue is that localised oil temperatures will be considerably higher than the temperature recorded in the sump by the OQS.

Rubish. For a modern automotive specific engine oil - its optimum operating temperature is in excess of 80-85 deg C. If the oil drops below 60deg C, it noticeably looses some of its lubricating abilites.

wrong, again, I won't call it 'rubbish', just lack of knowledge... oil should operate around 160 to 200, avg 180F (82C)...so if it in the sump at 200-220, guess what a 20-40 differential does?

Sorry; that upper limit of 200deg F IS utter old skool rubbish - for old skool MINERAL oils, and not modern high quality synthetics. Let me state again - VW standard 503.00 and above all comply to a HTHS rating which MUST exceed 150deg C. Just because yankie API standards are only rated to 100deg C max - that categorically does NOT mean that all oils must follow suit.

an additional HTHS - or 'High Temperature, High Shear' test - so won't be an issue. And then contamination - if your oil contains enough 'contaminents' to lessen the lubricating qualities of the oil, then either there is a problem with filtration (no element, damaged filter medium, or incorrect filter), or the oil is massively beyond its sheduled oil change interval.

still a fact, whether you agree or not...you think oil temp is the only factor in it's performance? what if it had sand in it? lol

Now you are being downright silly.

And you are also trying to misquote what I said. Where, exactly, do I either state or imply that "oil temp is the only factor in it's performance"?

[Teutonic_Tamer]

I saw 109 Celsius on Thursday after a spirited drive, and it was only 12 Celsius air temperature.

I can fully accept that.

I can routinely see oil temps in the high 120s C after many differing scenarios; be it a 'spirited' drive in the Alps, or long runs at v-max on German autobhans - even when ambients are below freezing.

This 'mentality' of thinking your engine will self destruct when your oil temp exceeds say 110deg C is, IMVHO, just pure and utter scare tactics.

[P_G]

OK, this is getting a bit out of hand. TT, accepting what you are suggesting in your posts and putting aside the virtual ferocity of some of your replies if VAG type approved oils and I'll be specific in the 5W-30 oil for our RS4's what is the contributing factor to the requisite 9.6 litres need to fill our engines requiring up to a litre top up of oil anywhere from 600 miles upwards?

Degradation of the oil? Vapourisation? And what effects does higher temperatures in your opinion have on frequency of this?

And if it is degredation would it not be fair to say that with degredation comes a de-optimasation of the oil's properties to lubricate which could be mitigated by changing oil regularly or using a spec more suited to frequent oil changes as opposed to long life oil which Castrol Mobile 1 ESP et al are i.e. an oil that gives better lubricating and protection performance over a shorter life in a yield over life cycle scenario for example?

[ArthurPE]

Nope - you stated Farenheight (sp?) - being as the planet beyond the USA uses Centigrade (OK - correct term Celcius) - I, and I guess others have difficulty in understanding deg F figures.

my gauge is in deg F

Sorry - but that is utter nonsence. I kindly ask you too correctly look up the definition of "flashpoint". Flashpoint specifically referrs to vapours - ie, a substance who's physical state is a GAS. Automotive engines soley rely on LIQUID state lubricants.

"Flashpoint", "volatility", and "vapour point" are three very differing fluid properties - and you seem to be confusing the attributes of one property with another.

Finally; care to enlighten us on exactly what 'hot' part of an engine can vapourise a high quality oil?

I would agree, 'nonsense/gibberish' does apply to your comments in this case
I'm guessing there is a reason all oils spec flashpoint?
blow-by is both gas and liquid droplets...it's flashed to vapor on the underside of the pistons...burning off the volitiles is how deposits and some sludges form...the likelyhood increase as oil is contaminated, fuel, etc., as the flashpoint decreases

My point is that the oil gets considerably hotter than the figure shown in the DIS. So, going by your logic, and from an earlier misleading post about oil braking down around 120deg C - then we'd be digging out lumps of coal from our sumps, rather than draining a liquid.

I never said that oil breaks down at 250F, someone else did, I refuted it
but I do maintain the sump is an avergae oil temp for the system, prior to the oil cooler, since it the largest volume in play

My point on the turbos is that the very same oil that is specified for our B7 RS4s is exactly the same oil specified in other very high performance Audis with turbos.

irrelavent then, as it is now

And your comment on turbos being water cooled - well some are - but some are categorically not. And let's be quite clear - a water cooled turbo uses a water jacket on the outer edges of the bearing housings. The hottest part of a turbo - the exhaust gas turbine is categorically not water cooled - the primary way the exhaust turbine is cooled is via the oil for the bearings.

the water jackets usually surround the oil paths, hence cool the oil and bearings...never said that the turbing volute was water cooled...but nope, oil only serves to cool/float the bearings, air is the primary cooling for the volute, and water to some extent, then oil...

It is a bit of a moot point weather the underside of a piston, or a turbo bearing is the 'hottest'. The crucial issue is that localised oil temperatures will be considerably higher than the temperature recorded in the sump by the OQS.

and I agree, and will exceed flashpoint depnding on the state of the oil, leaving deposits behind


Sorry; that upper limit of 200deg F IS utter old skool rubbish - for old skool MINERAL oils, and not modern high quality synthetics. Let me state again - VW standard 503.00 and above all comply to a HTHS rating which MUST exceed 150deg C. Just because yankie API standards are only rated to 100deg C max - that categorically does NOT mean that all oils must follow suit.

so now we insult the American, class act you are, now THAT is rubbish...oil does not operate at 300F, not for long...mine operates ~200F, as do most cars, 180 to 200, pretty much +10 over water temp...it's controlled by a thermostat and regulated to a relativly tight band...for a reason..


Now you are being downright silly.

it would seem to apply equally well to you and your positions, do we really need to resort to insults and personal attacks when talking about oil? it's moronic

And you are also trying to misquote what I said. Where, exactly, do I either state or imply that "oil temp is the only factor in it's performance"?

your post speaks for itself

[PetrolDave]

This 'mentality' of thinking your engine will self destruct when your oil temp exceeds say 110deg C is, IMVHO, just pure and utter scare tactics.

+1

What I will add is that I have seen a correlation between higher oil temps under normal driving conditions and two factors:

1) oil level. When the oil needs topping up (1/2 to 1 litre below max on the dipstick), oil temperatures are approx 5 Celsius higher. Not surprising really

2) time since last oil change. Even with the amount of oil the RS4 engine uses the characteristics of the oil do change and in my experience oil usage and oil temperatures increase with time after service, suggesting that regular oil changes are beneficial.

[P_G]

Dave, I'm glad you have said that as this is what I see and is what I was referring to in my post directed at TT.

Hence why I asked TT as he appears to know a lot more about oil properties and oil chemistry why this happens when my car runs at higher oil temperatures.

For example during this winter and temps the oil temp has by DIS averaged 92 degrees C (max 105 when pushing on hard) and I have not had to top the oil up at all yet in summer when running average 99 degrees C and easily getting up to 110-115 my RS needs 1 litre probably every 2-3k miles?

So knowing longlife 5W-30 oil is a fair bit thinner for a non technical term than some 'normal' synthetic 5W-30 oil would the latter and changed more often not be better?

[ArthurPE]

I just had mine for a hard run...upgrade , 3rd and 4th gear, 5k to 7k rpm...
drove around for an ~hour, then pulled onto a side road, less cooling, slower speed, the highest it got while pushing was 210F, w/heat soak 215F...brief periods at 300F is probably OK, sustained occassionally at 250F may not be bad, but imo, that does required decreased service intervals...and Audi's recommended of 10k miles is bad advice in my opinion, I do mine at 5k

also took some nice pics which I'll post later

[Teutonic_Tamer]

OK, this is getting a bit out of hand.

It's only the 'scare mongerers' who are letting it get out of hand!

TT, accepting what you are suggesting in your posts and putting aside the virtual ferocity of some of your replies if VAG type approved oils and I'll be specific in the 5W-30 oil for our RS4's what is the contributing factor to the requisite 9.6 litres need to fill our engines requiring up to a litre top up of oil anywhere from 600 miles upwards?

OK - two issues.

Firstly, there is an informally accepted 'industry standard' (amongst Euro and Jap manufacturers) that a 'tollerated' level of oil consumption can be upto a maximum of 1 litre of oil per 1000km (which is nigh-on 600miles). So, whilst a litre every 600 miles might seem boarderline, even extreme - if the RS4 drinks a litre say every 1000 to 2000 miles - that really isn't a problem.

Secondly, the specifics of why the RS4 engine drinks a lot of oil. The V8 block is not constructed from cast iron like 'conventional' engines - it is actually made from a high-grade aluminium alloy - Alusil. One of the properties of Alusil is the way the cylinder bores are honed. The honing process makes for an increadibly 'hard' surface to the cylinder bore, but which also contains quite deep (comparitively speaking, when viewed under a microscope) 'hollows'. These hollows in the bore will actually hold a significant quantity of oil - and this will get burned off during normal combustion. However, as the engine thoroughly 'beds in', the cylinder bores will become smoother, the quantity of oil collecting on the bores will diminish, and so oil consumption will reduce.

So, if an RS4 is still consuming noticeable quantities of oil after say 10-15k miles - then it honestly hasn't been truely run in.

My particular RS4 used to drink a litre every 1000-ish miles until about 5k miles (IIRC, it actually drunk 2½ litres in the first 2k miles). Oil consumption progressively reduced - and from around 12k-ish miles, consumes about 100-200ml per 1000 miles.

Degradation of the oil? Vapourisation? And what effects does higher temperatures in your opinion have on frequency of this?

If 504.00 oils are used - then degredation nor vapourisation categorically do NOT occur (well not beyond the strict acceptable limits). And referring to high oil temperatures - if and when you routinely see OVER 150deg C oil temperatures, then start to be concerned. But if you regularly see 120-130deg C - do NOT worry - 504.00 spec oils are specifically designed to operate contunuously at such temperatures.

And if it is degredation would it not be fair to say that with degredation comes a de-optimasation of the oil's properties to lubricate which could be mitigated by changing oil regularly or using a spec more suited to frequent oil changes as opposed to long life oil which Castrol Mobile 1 ESP et al are i.e. an oil that gives better lubricating and protection performance over a shorter life in a yield over life cycle scenario for example?

Firstly, there is NO proven data to support these rash claims that 504.00 oil is prematurely degredating.

Secondly, longlife oils can NOT be bettered by non longlife oils - period. It is by the very nature of longlife oils - that they do NOT 'break down'. 504.00 oils have a certified duration of 650 hours. 'Conventional' Mobil 1 (which is 502.00 rated) only has a rather pathetic duration of 128 hours - and even then, it looses upto 20% efficiency. With the VW longlife standards, even at the 650 hour duration, the oil MUST stay 'in grade' (I think the tollerance is around 96%). So it really is very old skool attitudes who think longlife oils are shyte!

By all means, definately do NOT use the 'LongLife servicing schedule' (use the 'Time and Distance' instead), but DO continue to use a high quality European originated 504.00 oil.

[Teutonic_Tamer]

Sorry; that upper limit of 200deg F IS utter old skool rubbish - for old skool MINERAL oils, and not modern high quality synthetics. Let me state again - VW standard 503.00 and above all comply to a HTHS rating which MUST exceed 150deg C. Just because yankie API standards are only rated to 100deg C max - that categorically does NOT mean that all oils must follow suit.

so now we insult the American, class act you are, now THAT is rubbish...oil does not operate at 300F, not for long...mine operates ~200F, as do most cars, 180 to 200, pretty much +10 over water temp...it's controlled by a thermostat and regulated to a relativly tight band...for a reason..

It has jack schit to do with 'insulting Americans'! It is simple FACTS. American API standards only test oil up to 100 deg C, whereas the European ACEA ratings, when the HTHS additional test is specified test the oil to 150 deg C.

I really don't know how you construe someone who posts facts as somehow co-relating to insulting a particular nation! Hey ho!

[ArthurPE]

It has jack schit to do with 'insulting Americans'! It is simple FACTS. American API standards only test oil up to 100 deg C, whereas the European ACEA ratings, when the HTHS additional test is specified test the oil to 150 deg C.

I really don't know how you construe someone who posts facts as somehow co-relating to insulting a particular nation! Hey ho!

ok 'yankie'

limey

[P_G]

Both of you chill out and keep it factual as you both seem to want to campaign.

[Shoppinit]

I have seen a correlation between higher oil temps under normal driving conditions and two factors:

1) oil level. When the oil needs topping up (1/2 to 1 litre below max on the dipstick), oil temperatures are approx 5 Celsius higher. Not surprising really

2) time since last oil change. Even with the amount of oil the RS4 engine uses the characteristics of the oil do change and in my experience oil usage and oil temperatures increase with time after service, suggesting that regular oil changes are beneficial.

I also noticed a drop in oil temp of about 7-8°C after changing my plugs. I'm not really sure what the explanation is for this. Those running high temps, when were your plugs last changed?

[ArthurPE]

I also noticed a drop in oil temp of about 7-8°C after changing my plugs. I'm not really sure what the explanation is for this. Those running high temps, when were your plugs last changed?

that is strange...
perhaps it's not the plugs per se, but after a few 1000 miles, they loosen up a bit and unmetered air is being pulled in and it's running a bit lean, and therefore hotter, raising the oil temp...
but since the oil temp is thermostatically controlled, that doesn't make sense?