High Temp/High Shear Viscosity and Fuel Efficiency Under Steady State Conditions
- Thread starter TooSlick
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Ted, as a professional bodybuilder (
) let me say my Audi can't and won't ever run 5W-20, unless you can brew one that has an HTHS of 3.5 or better. The lowest I can run according to the manual is 5W-30, and that comes with the warning regarding prolonged high speed driving at high ambient temperatures. You know as well as I do, sticking with the manufacturer's minimum requirements is paramount. If Honda recommends 0W-20, will you use a 0W-10 oil (if that even exists) to save another 1% fuel?
How about YOU put some 5W-20 in YOUR Audi and let us know how it works out?
Still, I completely agree on the temperature/oil chart that German carmakers generally provide, though with the now common 2 year service intervals, 0W-30/40 and 5W-40 oils seem to have become the most common viscosities for newer cars in Central Europe, since they obviously represent the best compromise for a four-season oil.
Still, I completely agree on the temperature/oil chart that German carmakers generally provide, though with the now common 2 year service intervals, 0W-30/40 and 5W-40 oils seem to have become the most common viscosities for newer cars in Central Europe, since they obviously represent the best compromise for a four-season oil.
It blows me away that SO many people seem concerned about fuel economy, yet the vast majority of vehicles I see were surely rated less than 25MPG when new.
Dave
Dave
Tooslick, would you please post what weight oils Audi/VW reccomends for each temp range, or is there a link to it?
Thanks!
Thanks!
As my wife always says, "we aren't communicating"
Run the Mobil 1R, 0w-30 ....it will be your best combination of subjective engine performance and enhanced valvetrain protection. If you are concerned about the price per quart, simply increase you drain intervals by 50% over what you were running.
The very expensive Series 2000, 0w-30 is Amsoils most cost effective oil for 90% of my customers, due to enhanced fuel efficiency and greatly extended drain intervals. ExxonMobil has copied this same basic approach and should be given credit for doing so. Don't sweat the greatly increased ZDDP levels, they are exactly the right approach.
How do I know the M-1R will easily last 50% longer in service?
[ February 19, 2004, 02:18 PM: Message edited by: TooSlick ]
Run the Mobil 1R, 0w-30 ....it will be your best combination of subjective engine performance and enhanced valvetrain protection. If you are concerned about the price per quart, simply increase you drain intervals by 50% over what you were running.
The very expensive Series 2000, 0w-30 is Amsoils most cost effective oil for 90% of my customers, due to enhanced fuel efficiency and greatly extended drain intervals. ExxonMobil has copied this same basic approach and should be given credit for doing so. Don't sweat the greatly increased ZDDP levels, they are exactly the right approach.
How do I know the M-1R will easily last 50% longer in service?
[ February 19, 2004, 02:18 PM: Message edited by: TooSlick ]
Thanks Tooslick! That is very interesting! According to VW, just about everyone using conventional oil is using one that is too thin.
Ted, you state that A3 ratings are important for extended drains and then say to use the M-1R for extended drains to save $/qt. But, the M-1R is not A3 rated. I'm confused?
Obviously all the ZDDP (nor moly for that matter) in the world isn't increasing the HT/HS. Same for Redline...
Additionally, you will still get other negative effects from running too thin a viscosity such as increased volatily, burn-off, sludge and consumption. So you can only carry the things so far with respect to thin viscosity/high HT/HS.
Obviously all the ZDDP (nor moly for that matter) in the world isn't increasing the HT/HS. Same for Redline...
Additionally, you will still get other negative effects from running too thin a viscosity such as increased volatily, burn-off, sludge and consumption. So you can only carry the things so far with respect to thin viscosity/high HT/HS.
self delete.
Fred..
[ February 19, 2004, 05:14 PM: Message edited by: palmerwmd ]
Fred..
[ February 19, 2004, 05:14 PM: Message edited by: palmerwmd ]
Actually, there are some HDEO's that are friction modified. Mobil Delvac 1 has claimed fuel economy improvements of 3% over the "base" 15W-40 for years now.
Esso XD-3 15W-40 also claims some fuel economy improvement- around 1-2%. The Esso XD-3 0W-30 and 0W-40 PAO's claim similar gains.
Most HDEO blenders don't put in "energy conserving" additives as they usually contribute to Top Grove Fill in HD diesel engines.
FWIW: when I ran Mobil Delvac 1 5W-40 in my 1992 Honda Prelude SR during a summer road trip, there was NO differnce in MPG that I could determine.
For a difference of 1-2%, most of us wouldn't even notice it or put it within statistical variance.
Jerry
Hi,
TooSlick - a pity this thread fell of the rails a bit it was good, but sometimes I get confused by your posts take this as an example;
You said -As a mechanical engineer, the German manufacturers, viscosity/temp charts make the most sense to me ....the same Audi engine can run anything from a 5w-20 to a 20w-50, depending on ambient temps ....
and then;
You said - I was about fifteen years ahead of VW/Audi in moving to low viscosity synlubes and have primarily run the xw-30 grades year round in my Audi/VW engines since 1985
Ted, VW have been an advocate of the lighter oil grades for several decades even before Audi was acquired - from the aircooled engines' 20w-20 or 30 - to their own first coolant cooled engines. They have always used viscosity to temperature charts too - like most Euro makers - Peugeot, Renault, FIAT, Volvo, etc the list goes on... do - not only the Germans. I refer you too to the earlier vehicle post here concerning Fords, Chevs etc where oil recommendations were published
And these charts being quite simple to follow do not require an owner to be an Engineer!
But even more confusing is that perhaps some of your content in this thread may be up for mis-interpretation and I would not like this to be the case for the sake of the reader
1 - Oil pressure
The comments about oil pressure changing with wear needs some qualification - some may even say your comments are wrong - I think they can be misinterpreted
a) oil pressure depends on the design of the lubrication system and it is not a variable or a user controlled function as may be suggested from the tenor of your posts.
Variances with wear will be very hard to pick up if not impossible without noting below
b) reliable oil pressure readings can only be taken using a master gauge of known calibration and quality
c) oil pressure measurement parameters are set by the manufacturer and these vary;
c1 - measured at idle,
c2 - measured at 1k, or 2k rpm and etc,
c3 - and a perhaps even a matrix of these plus other factors
d) oil pressure measurements are normally taken under controlled circumstances;
d1 - manufacturer's specified oil - viscosity/type - in the sump
d2 - oil temperature must be at ?
d3 - coolant temperature must be at ?
d4 - and perhaps both of d2 and d3
Internal lubrication system factors other than wear - such as a restricted oil pump screen etc - also need to be eliminated when making meaningful end result assessments
I have had engines that have run out to 1m miles and there has been NO oil pressure reduction from new until then. The oil's type and viscosity has always remained constant in that time
Oil pressure will go down or up according to the viscosity used, the ambient temperature, use factors etc but it must always be sheeted back to the above for accurate assessment
Low idle oil pressure with a 40C ambient and after climbing a long hill will usually be a non event if c1,c2 or c3 above is known and met and the standard oil pressure warning light is not on!
This is just one reason why most cars do NOT have an oil pressure gauge fitted - a lack of user understanding and knowledge - and why the oil warning pressure light is almost universal.
It's trigger pressure indicates what the engine manufacturer deems to be a critical low pressure but usually with a small margin too
Many modern engines will decrease power in such a critical case - so judging oil pressure at idle should be done with extreme caution if it is done at all in isolation
It is true that some German manufacturers use higher than average oil pressure on some engines but the 25psi per 1000rpm is a suspect comment. Even with a relief valve set at 9bar or about 130 psi - this probably would never be reached in a hot engine using the correct lubricant, and needs it to be a known amongst those factors listed above.
Typically an engine's manufacturer will state: example only ...the reading should be 5bar+/- 0.5 at 3000rpm... and of course when using those factors noted in d above
So Ted have you measured your own car's actual oil pressure in a matrix of revs/temperatures and according to the manufacturers criteria? - because the pegged figure will only show the limits of the gauge and not what the true pressure is - so your statements may be mis-leading
2 - Wear Metals
It is indeed difficult if not impossible to state what a wear metal rate per 1k may be unless many qualifiers are also mentioned at the same time
a) the metallurgy contained in the wearing components of the engine family must be known
You cannot apply the GM V8 wear rates against a BMW V8 and some maker's rate copper above lead, some do not rate copper and etc.
b) the acceptable wear rates for an engine family must be known
c) the ppm rate has more to do with 2 a, b, above and has little to do with;
- engine capacity - - engine type - inline 4,6, V6, V8, H4, H6, DOHC, SOHC, SV and etc etc.
As an example I have seen iron at 20ppm described on here as ..too high.. or ...acceptable... Or, ...heavy diesels with large oil capacity can handle 130ppm but a small engine with a smaller oil capacity cannot...!
I wonder against what parameters such comments are made?
A ppm reading is just that, a ppm reading - regardless!
d) wear rates have much to do with engine application and use factors too which are far too broad to cover here
Example; one engine family may have perfectly acceptable iron reading of Constant load/constant speed engines being compared to another engine's use is another example where acceptable rates will vary substantially
e) wear trends from UOA's which are administered in a calculated and controlled manner do indeed assist engine condition monitoring. But they must be based only based on the above criteria and with engine family experience
Many persons on this Board do not track wear metal trends and the taking of single samples for UOA's along with using oils of different types and viscosities at each OC make the monitoring task difficult if not impossible
General comparisons between similar engines should/can only be used as guidelines drawn between the recorded highs and lows contained in historical and meaningful data.
"Spikes" caused by a variety of factors may be noticed if the engine's history is known and available. These should be analysed and then acted upon if required
So Ted, generalising on wear metals may give a wrong impression to many and may be misleading to others unless appropriately qualified
Being able to track an engine's individual component wear rate and then replace it before failure is unfortunately still a dream - one that is not going to achievable for some time yet. But CATERPILLAR started that dream off three or more decades ago for all of us!
Engine failure caused through excessive wear is less common today than ever before. Today it is rather more a case of a sudden engine failure caused by component fatigue, poor maintenance such as incorrect lubricant, no coolant care, a cam belt breaking etc, user driver/abuse - over revving, towing excessive weights etc etc. or breakage such a dropped valve head etc.- or even perhaps some of each!
Engines still wear out of course but this is not really a failure - just a mechanical reality!
And as we know from the various posts on here it really matters very little what correct spec. oil you use - mineral or synthetic - except perhaps at the extremes of application. As long as the oil is changed in a controlled manner and normal and reasonable engine maintenance is undertaken engine life is usually well beyond vehicle ownership life in any event. And this is despite what by-pass filters and other devices we add on to today's well designed and produced engines. Yes, and even GM's V8s too!
Perhaps we should try to keep things in balance
3 - Fuel economy - in the real world!
Finally as stated by somebody else here, Driver behaviour - and their knowledge - overrules all else in the fuel economy stakes. I have spent since 1975 in the Professional Driver training arena - that is my business T'a Road Transport & Training Resources P/L - and I can confirm as Daimler Benz found out many years ago it is poor Driver behaviour that can nullify almost every piece of new technology - and very quickly too. The Daimler Benz driver simulator in Berlin has nearly two decades of history behind it - with both cars and trucks!
In GENERAL TERMS then oil choice has only a minor impact on fuel economy - perhaps not even as much as a dirty air cleaner element and possibly much less. I keep the best records possible for my truck fleet and we could not detect a difference in moving to Delvac 1 - unfortunately too many other factors are at play in the real world!
Just some other things to consider
Regards
TooSlick - a pity this thread fell of the rails a bit it was good, but sometimes I get confused by your posts take this as an example;
You said -As a mechanical engineer, the German manufacturers, viscosity/temp charts make the most sense to me ....the same Audi engine can run anything from a 5w-20 to a 20w-50, depending on ambient temps ....
and then;
You said - I was about fifteen years ahead of VW/Audi in moving to low viscosity synlubes and have primarily run the xw-30 grades year round in my Audi/VW engines since 1985
Ted, VW have been an advocate of the lighter oil grades for several decades even before Audi was acquired - from the aircooled engines' 20w-20 or 30 - to their own first coolant cooled engines. They have always used viscosity to temperature charts too - like most Euro makers - Peugeot, Renault, FIAT, Volvo, etc the list goes on... do - not only the Germans. I refer you too to the earlier vehicle post here concerning Fords, Chevs etc where oil recommendations were published
And these charts being quite simple to follow do not require an owner to be an Engineer!
But even more confusing is that perhaps some of your content in this thread may be up for mis-interpretation and I would not like this to be the case for the sake of the reader
1 - Oil pressure
The comments about oil pressure changing with wear needs some qualification - some may even say your comments are wrong - I think they can be misinterpreted
a) oil pressure depends on the design of the lubrication system and it is not a variable or a user controlled function as may be suggested from the tenor of your posts.
Variances with wear will be very hard to pick up if not impossible without noting below
b) reliable oil pressure readings can only be taken using a master gauge of known calibration and quality
c) oil pressure measurement parameters are set by the manufacturer and these vary;
c1 - measured at idle,
c2 - measured at 1k, or 2k rpm and etc,
c3 - and a perhaps even a matrix of these plus other factors
d) oil pressure measurements are normally taken under controlled circumstances;
d1 - manufacturer's specified oil - viscosity/type - in the sump
d2 - oil temperature must be at ?
d3 - coolant temperature must be at ?
d4 - and perhaps both of d2 and d3
Internal lubrication system factors other than wear - such as a restricted oil pump screen etc - also need to be eliminated when making meaningful end result assessments
I have had engines that have run out to 1m miles and there has been NO oil pressure reduction from new until then. The oil's type and viscosity has always remained constant in that time
Oil pressure will go down or up according to the viscosity used, the ambient temperature, use factors etc but it must always be sheeted back to the above for accurate assessment
Low idle oil pressure with a 40C ambient and after climbing a long hill will usually be a non event if c1,c2 or c3 above is known and met and the standard oil pressure warning light is not on!
This is just one reason why most cars do NOT have an oil pressure gauge fitted - a lack of user understanding and knowledge - and why the oil warning pressure light is almost universal.
It's trigger pressure indicates what the engine manufacturer deems to be a critical low pressure but usually with a small margin too
Many modern engines will decrease power in such a critical case - so judging oil pressure at idle should be done with extreme caution if it is done at all in isolation
It is true that some German manufacturers use higher than average oil pressure on some engines but the 25psi per 1000rpm is a suspect comment. Even with a relief valve set at 9bar or about 130 psi - this probably would never be reached in a hot engine using the correct lubricant, and needs it to be a known amongst those factors listed above.
Typically an engine's manufacturer will state: example only ...the reading should be 5bar+/- 0.5 at 3000rpm... and of course when using those factors noted in d above
So Ted have you measured your own car's actual oil pressure in a matrix of revs/temperatures and according to the manufacturers criteria? - because the pegged figure will only show the limits of the gauge and not what the true pressure is - so your statements may be mis-leading
2 - Wear Metals
It is indeed difficult if not impossible to state what a wear metal rate per 1k may be unless many qualifiers are also mentioned at the same time
a) the metallurgy contained in the wearing components of the engine family must be known
You cannot apply the GM V8 wear rates against a BMW V8 and some maker's rate copper above lead, some do not rate copper and etc.
b) the acceptable wear rates for an engine family must be known
c) the ppm rate has more to do with 2 a, b, above and has little to do with;
- engine capacity - - engine type - inline 4,6, V6, V8, H4, H6, DOHC, SOHC, SV and etc etc.
As an example I have seen iron at 20ppm described on here as ..too high.. or ...acceptable... Or, ...heavy diesels with large oil capacity can handle 130ppm but a small engine with a smaller oil capacity cannot...!
I wonder against what parameters such comments are made?
A ppm reading is just that, a ppm reading - regardless!
d) wear rates have much to do with engine application and use factors too which are far too broad to cover here
Example; one engine family may have perfectly acceptable iron reading of Constant load/constant speed engines being compared to another engine's use is another example where acceptable rates will vary substantially
e) wear trends from UOA's which are administered in a calculated and controlled manner do indeed assist engine condition monitoring. But they must be based only based on the above criteria and with engine family experience
Many persons on this Board do not track wear metal trends and the taking of single samples for UOA's along with using oils of different types and viscosities at each OC make the monitoring task difficult if not impossible
General comparisons between similar engines should/can only be used as guidelines drawn between the recorded highs and lows contained in historical and meaningful data.
"Spikes" caused by a variety of factors may be noticed if the engine's history is known and available. These should be analysed and then acted upon if required
So Ted, generalising on wear metals may give a wrong impression to many and may be misleading to others unless appropriately qualified
Being able to track an engine's individual component wear rate and then replace it before failure is unfortunately still a dream - one that is not going to achievable for some time yet. But CATERPILLAR started that dream off three or more decades ago for all of us!
Engine failure caused through excessive wear is less common today than ever before. Today it is rather more a case of a sudden engine failure caused by component fatigue, poor maintenance such as incorrect lubricant, no coolant care, a cam belt breaking etc, user driver/abuse - over revving, towing excessive weights etc etc. or breakage such a dropped valve head etc.- or even perhaps some of each!
Engines still wear out of course but this is not really a failure - just a mechanical reality!
And as we know from the various posts on here it really matters very little what correct spec. oil you use - mineral or synthetic - except perhaps at the extremes of application. As long as the oil is changed in a controlled manner and normal and reasonable engine maintenance is undertaken engine life is usually well beyond vehicle ownership life in any event. And this is despite what by-pass filters and other devices we add on to today's well designed and produced engines. Yes, and even GM's V8s too!
Perhaps we should try to keep things in balance
3 - Fuel economy - in the real world!
Finally as stated by somebody else here, Driver behaviour - and their knowledge - overrules all else in the fuel economy stakes. I have spent since 1975 in the Professional Driver training arena - that is my business T'a Road Transport & Training Resources P/L - and I can confirm as Daimler Benz found out many years ago it is poor Driver behaviour that can nullify almost every piece of new technology - and very quickly too. The Daimler Benz driver simulator in Berlin has nearly two decades of history behind it - with both cars and trucks!
In GENERAL TERMS then oil choice has only a minor impact on fuel economy - perhaps not even as much as a dirty air cleaner element and possibly much less. I keep the best records possible for my truck fleet and we could not detect a difference in moving to Delvac 1 - unfortunately too many other factors are at play in the real world!
Just some other things to consider
Regards
Before VW/Audi, "dumbed down" their lube recommendations, they used to list a whole spectrum of grades, depending on the ambient temps you were likely to see for the next oil change intervals:
Note: these recs are for conventional oils and not synthetics*
1996-1999 Vw/Audi Engines:
All temps* ...5w-50/10w-50/10w-60
Above 5F*...15w-40/15w-50/20w-40/20w-50
Below 60F* ...5w-30/5w-40/10w-30/10w-40
Energy Conserving Oils - read as Synthetics:
All Temps: 5w-30/10w-30/5w-40/10w-40
What Vw/Audi did after Model Year 2000 is to grossly simplify the above charts and they now list 5w-30 and 5w-40 for all temps. My 2002 Audi TT turbo actually recommends a VW 502 rated, 0w-30 synthetic as the primary lube and lists 5w-30/5w-40 as alternate grades.
I was about fifteen years ahead of VW/Audi in moving to low viscosity synlubes and have primarily run the xw-30 grades year round in my Audi/Vw engines since 1985. This includes my 1985 Jetta, 1985 Audi 5000, 1990 Audi 100, 1997 Vw Jetta and now my 2002 Audi TT turbo. That period since 1985 included very high temp use in the Mohave Desert and fifteen years in Alabama ....The "take home" message is that a 11.5-12.0 Cst, xw-30 synthetic, running at 200F, will give you the same oil film thickness as a 14-15 Cst, 15w-40 petroleum oil running @ 220F, or a 20w-50 petroleum "racing" oil; running @ 240F. There is an excellent viscosity/temp chart on the Redline Oil website for their racing oils that illustrates this principle ....The Honda/Ford lube engineers that now recommend 5w-20 instead of 5w-30/10w-30 are also very aware of this fact!
Reducing peak oil temps increases power, reduces wear/deposits, reduces oil consumption, reduces pinging in hot weather, and increases the life of elastomeric seals and gaskets. It's all good ....
TS
[ February 19, 2004, 12:24 PM: Message edited by: TooSlick ]
Note: these recs are for conventional oils and not synthetics*
1996-1999 Vw/Audi Engines:
All temps* ...5w-50/10w-50/10w-60
Above 5F*...15w-40/15w-50/20w-40/20w-50
Below 60F* ...5w-30/5w-40/10w-30/10w-40
Energy Conserving Oils - read as Synthetics:
All Temps: 5w-30/10w-30/5w-40/10w-40
What Vw/Audi did after Model Year 2000 is to grossly simplify the above charts and they now list 5w-30 and 5w-40 for all temps. My 2002 Audi TT turbo actually recommends a VW 502 rated, 0w-30 synthetic as the primary lube and lists 5w-30/5w-40 as alternate grades.
I was about fifteen years ahead of VW/Audi in moving to low viscosity synlubes and have primarily run the xw-30 grades year round in my Audi/Vw engines since 1985. This includes my 1985 Jetta, 1985 Audi 5000, 1990 Audi 100, 1997 Vw Jetta and now my 2002 Audi TT turbo. That period since 1985 included very high temp use in the Mohave Desert and fifteen years in Alabama ....The "take home" message is that a 11.5-12.0 Cst, xw-30 synthetic, running at 200F, will give you the same oil film thickness as a 14-15 Cst, 15w-40 petroleum oil running @ 220F, or a 20w-50 petroleum "racing" oil; running @ 240F. There is an excellent viscosity/temp chart on the Redline Oil website for their racing oils that illustrates this principle ....The Honda/Ford lube engineers that now recommend 5w-20 instead of 5w-30/10w-30 are also very aware of this fact!
Reducing peak oil temps increases power, reduces wear/deposits, reduces oil consumption, reduces pinging in hot weather, and increases the life of elastomeric seals and gaskets. It's all good ....
TS
[ February 19, 2004, 12:24 PM: Message edited by: TooSlick ]
I stopped using Syntec 10W-30, because I realized that even though the old data sheets I had showed it having an HT/HS of 3.5, it went to a 20wt. quickly. I liked all the other characteristics.
I think the newer data sheets show lower anyway.
I've went to M1 10W-30 and it pretty much stays put.
Like TooSlick says, the thinning out seems to be designed in.
I'm on a budget, so $4 a qt. for M1 works for me. I do think the 3.5, friction modified would be ideal.
Maybe I can add a quart or M1 15/50 this Summer to up it a bit?? What do you think??
I've went to M1 10W-30 and it pretty much stays put.
Like TooSlick says, the thinning out seems to be designed in.
I'm on a budget, so $4 a qt. for M1 works for me. I do think the 3.5, friction modified would be ideal.
Maybe I can add a quart or M1 15/50 this Summer to up it a bit?? What do you think??
Hi Last_Z
its in the post !
Regards
Doug
its in the post !
Regards
Doug
These were just intended to be general comments about the relationship of HT/HS viscosity and fuel efficiency....
These new xw-20 grades have HT/HS in the 2.6-2.9 Cp range, compared to 3.0-3.3 Cp for most xw-30 oils. Fuel savings under actual driving conditions range from 1.0%-2.5%,depending on the duty cycle of the engine and the ambient temps. The CCS viscosities of the 5w-20 grades also tend to be lower than for the 5w-30 grades - this saves fuel during the warmup phase.
As for the M-1R ... the amount of fuel that is consumed from running a 650 Hp, small block V-8 @ 200 mph for 500 miles is tremendous. I'd bet it is equal to running many thousands of miles on the street. The rate of oil oxidation also doubles for every 10C increase in oil temps. So if you are running sustained 150C oil temps, instead of 90C oil temps, you have sixty four times the rate of oxidation. I don't know if there is an exact correlation between cylinder head temps and the rate of nitration, but NOx production dramatically increases in a hot running engine.
It is these three mechanisms: fuel contamination,oxidation and nitration, that degrade engine oils in service.
The secondary reason why the M-1R is severely doped with ZDDP is to minimize oxidative thickening and the loss of power that results from this. If your 0w-30 oxidizes to a 70wt by the end of the race, you won't run very well.
If you have some insight into the basestock quality,amount of VI modifier - or lack thereof, and additive chemistry, it's not really necessary to test the M-1R to know it will hold up extremely well in street use. As Robert Zimmerman used to say, way back when: "It don't take a weatherman to know which way the wind blow ...."
These new xw-20 grades have HT/HS in the 2.6-2.9 Cp range, compared to 3.0-3.3 Cp for most xw-30 oils. Fuel savings under actual driving conditions range from 1.0%-2.5%,depending on the duty cycle of the engine and the ambient temps. The CCS viscosities of the 5w-20 grades also tend to be lower than for the 5w-30 grades - this saves fuel during the warmup phase.
As for the M-1R ... the amount of fuel that is consumed from running a 650 Hp, small block V-8 @ 200 mph for 500 miles is tremendous. I'd bet it is equal to running many thousands of miles on the street. The rate of oil oxidation also doubles for every 10C increase in oil temps. So if you are running sustained 150C oil temps, instead of 90C oil temps, you have sixty four times the rate of oxidation. I don't know if there is an exact correlation between cylinder head temps and the rate of nitration, but NOx production dramatically increases in a hot running engine.
It is these three mechanisms: fuel contamination,oxidation and nitration, that degrade engine oils in service.
The secondary reason why the M-1R is severely doped with ZDDP is to minimize oxidative thickening and the loss of power that results from this. If your 0w-30 oxidizes to a 70wt by the end of the race, you won't run very well.
If you have some insight into the basestock quality,amount of VI modifier - or lack thereof, and additive chemistry, it's not really necessary to test the M-1R to know it will hold up extremely well in street use. As Robert Zimmerman used to say, way back when: "It don't take a weatherman to know which way the wind blow ...."
Yes, ZDDP is also an anti-oxident and to add , the fast NASCAR V-8's have over 600lbs of open valve spring pressure ...no ordinary oil will keep a cam and horizontal locking bar roller lifters alive .
Tooslick,
Thanks for generating this thread and sharing some of your knowledge . Most don't understand racing engines and what it takes to protect them in terms of lubrication .
[ February 20, 2004, 04:21 PM: Message edited by: Motorbike ]
Hi,
it is possible that the cam wiping pressures on the V8 Supercars here are similar to NASCAR so I will make some enquiries and report later
M1 R has been excellent in that environment
Off hand I cannot remember what they are but the DD Series 60 valve gear pressures are extremely high too - hence the use of ceramic rollers
Regards
it is possible that the cam wiping pressures on the V8 Supercars here are similar to NASCAR so I will make some enquiries and report later
M1 R has been excellent in that environment
Off hand I cannot remember what they are but the DD Series 60 valve gear pressures are extremely high too - hence the use of ceramic rollers
Regards
Hi Doug:
Absolutely. I have also found in the "real world" that an oil that claims a fuel economy "improvement" of 1-3% over the "base reference oil" is simply NOT detectable by the average driver.
The 1-3%, say 1.5% on "average," easily falls within statistical variability. For example, assume the following hypothetical fuel economy results in miles per U.S. gallon:
8 MPG + 1.5% = 8.12 MPG
10 MPG + 1.5% = 10.15 MPG
15 MPG + 1.5% = 15.2 MPG
20 MPG + 1.5% = 20.3 MPG
30 MPG + 1.5% = 30.5 MPG
40 MPG + 1.5% = 40.6 MPG
50 MPG + 1.5% = 50.8 MPG
The thing is, in North America, the U.S. in particular, car makers test to EPA CAFE (Environmental "Protection" Agency Corporate AVERAGE Fuel Economy) standards.
The CAFE allows the car maker to apply hypothetical fuel economy "improvements" over literally hundreds of THOUSANDS of units. This allows the hypothetical MPG "improvement" to build CAFE "credits" to be applied to vehicles with dismal fuel economy.
So the CAFE "credits" with the heavily weighted formulae allows the car maker to ignore giant SUV's with dismal fuel economy. It helps that fuel prices are kept artificially low here compared to the rest of the world.
I've sent a few emails to the EPA asking for clarification of CAFE and the CAFE "credits" but have never received a response. I suppose the CAFE "credits" are some sort of "new math" that even my 4 years of college Calculus couldn't decipher.
Many other things have adverse effects on fuel economy. Doug noted the most important: the DRIVER. If you drive like a bloody idiot, you will get poor fuel economy!
Severe cold winter temps cut fuel economy in half, especially stop-n-go city driving at -40 C.
If your tires are improperly inflated - too low - you will experience FAR greater variability! As Doug mentioned, if the air filter is clogged, that makes a HUGE difference. Are the spark plugs fouled??
There are other good reasons to use a high quality synthetic oil: engine cleanliness, long life, extended OCI's, cold and hot temp extended protection, etc etc.
Indeed, I first started using Mobil Delvac 1 5W-40 in commercial HD diesel motors +20 years ago for just one reason: cold starts at -42 F. At the time, it was the only HDEO that could be safely used in temps from -42 F to hot summer ambient temps.
I have seen and still occasionally see blown motors when started at extreme cold temps using an oil that has frozen rock hard.
However, the latest reformulation of Delvac 1 to CI-4 (Controls severe soot loading from the use of EGR in HD diesel motors, an EPA mandated emissions change) appears to have severely thickened Delvac 1 in temps colder than -30 C.
I may have to switch back to Esso XD-3 0W-40 at least for the winter months. Since this will require OCI's twice a year, it will no longer be cost effective for me to continue using Delvac 1.
I'm sure the last thing Doug Hillary has to worry about is extreme cold temps. Unless we enter another ice age!
Jerry
Absolutely. I have also found in the "real world" that an oil that claims a fuel economy "improvement" of 1-3% over the "base reference oil" is simply NOT detectable by the average driver.
The 1-3%, say 1.5% on "average," easily falls within statistical variability. For example, assume the following hypothetical fuel economy results in miles per U.S. gallon:
8 MPG + 1.5% = 8.12 MPG
10 MPG + 1.5% = 10.15 MPG
15 MPG + 1.5% = 15.2 MPG
20 MPG + 1.5% = 20.3 MPG
30 MPG + 1.5% = 30.5 MPG
40 MPG + 1.5% = 40.6 MPG
50 MPG + 1.5% = 50.8 MPG
The thing is, in North America, the U.S. in particular, car makers test to EPA CAFE (Environmental "Protection" Agency Corporate AVERAGE Fuel Economy) standards.
The CAFE allows the car maker to apply hypothetical fuel economy "improvements" over literally hundreds of THOUSANDS of units. This allows the hypothetical MPG "improvement" to build CAFE "credits" to be applied to vehicles with dismal fuel economy.
So the CAFE "credits" with the heavily weighted formulae allows the car maker to ignore giant SUV's with dismal fuel economy. It helps that fuel prices are kept artificially low here compared to the rest of the world.
I've sent a few emails to the EPA asking for clarification of CAFE and the CAFE "credits" but have never received a response. I suppose the CAFE "credits" are some sort of "new math" that even my 4 years of college Calculus couldn't decipher.
Many other things have adverse effects on fuel economy. Doug noted the most important: the DRIVER. If you drive like a bloody idiot, you will get poor fuel economy!
Severe cold winter temps cut fuel economy in half, especially stop-n-go city driving at -40 C.
If your tires are improperly inflated - too low - you will experience FAR greater variability! As Doug mentioned, if the air filter is clogged, that makes a HUGE difference. Are the spark plugs fouled??
There are other good reasons to use a high quality synthetic oil: engine cleanliness, long life, extended OCI's, cold and hot temp extended protection, etc etc.
Indeed, I first started using Mobil Delvac 1 5W-40 in commercial HD diesel motors +20 years ago for just one reason: cold starts at -42 F. At the time, it was the only HDEO that could be safely used in temps from -42 F to hot summer ambient temps.
I have seen and still occasionally see blown motors when started at extreme cold temps using an oil that has frozen rock hard.
However, the latest reformulation of Delvac 1 to CI-4 (Controls severe soot loading from the use of EGR in HD diesel motors, an EPA mandated emissions change) appears to have severely thickened Delvac 1 in temps colder than -30 C.
I may have to switch back to Esso XD-3 0W-40 at least for the winter months. Since this will require OCI's twice a year, it will no longer be cost effective for me to continue using Delvac 1.
I'm sure the last thing Doug Hillary has to worry about is extreme cold temps. Unless we enter another ice age!
Jerry
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