...[ MOTOR YAĞI ile ilgili tüm paylaşımlar ]... | DonanımHaber Forum

...[ MOTOR YAĞI ile ilgili tüm paylaşımlar ]... - Sayfa 120

vezir · 2006-04-25T19:55:17.0000000+03:00

........ANKET KONUSU : Tercih ettiğiniz motor yağı markası nedir? Motor yağları hakkında alım hakkında karar verirken bilinmesi gerekenleri bu başlık altında yazmaya gayret edeceğim. Aslında bu bilgileri bulabileceğiniz çokça veri internette mevcuttur. Ancak fazla veri de konu hakkında çok fazla bilgisi olmayanların kafasını karıştırabilmektedir. Neye göre ve hangisi hangisinden daha önemli konuları için öncelikle bilinmesi gerekenleri link olarak vermeye çalışacağım . http://www.motor-yagi.com/? http://www.makinamerkezim.com/article/makine-yaglari-cesitleri-ozellikleri-yag-secimi-ve-makine-yag-bakim-egitimi/ Bu linkte detaylı bilgiler biraraya toplanmış http://www.mobiloil.com.tr/Turkey-Turkish-LCW/whichoil.aspx http://www.mobiloil.com.tr/Turkey-Turkish-LCW/carengineoils_which-oil.aspx http://www.castrol.com/tr_tr/turkey/motor-yagi-secici-hangi-araca-hangi-yag.html http://www.uzmantv.com/aracimiza-uygun-motor-yagini-nasil-secebiliriz https://www.youtube.com/watch?v=mmmcj53TNic https://en.wikipedia.org/wiki/Motor_oil https://en.wikipedia.org/wiki/Lubricant https://www.dieselnet.com/tech/lube.php yağ analizi hakkında bilinebilecek herşey linkte http://www.google.com.tr/url?sa=trct=jq=esrc=ssource=webcd=4cad=rjauact=8ved=0ahUKEwiN5NC9mvPNAhUFuxQKHa_MAL8QFgg7MAMurl=http%3A%2F%2Fwww.spectrosci.com%2Fdefault%2Fassets%2FFile%2FSpectroSci_OilAnalysisHandbook_FINAL_2014-08.pdfusg=AFQjCNFfK0v3TGipfNHsLvSwAoZy3jroww yabancı teknik kaynak http://www.toromontcat.com/pdf/oilengine.pdf

fsnn

Binbaşı

1195 Mesaj

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Stranger

Yarbay

2597 Mesaj

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fsnn

Binbaşı

1195 Mesaj

Tüm Başarılarını Gör

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

fsnn

Binbaşı

1195 Mesaj

Tüm Başarılarını Gör

Stranger

Yarbay

2597 Mesaj

Tüm Başarılarını Gör

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

fsnn

Binbaşı

1195 Mesaj

Tüm Başarılarını Gör

quote:

Orijinalden alıntı: StrangerXT

50bin lastik ömrü demek ha ?

http://www0.epinions.com/review/Michelin_LTX_M_S_Truck_SUV_Tire/auto-review-23BD-B28FDF0-39816EA0-prod4

al sana 100000 bin mil (mil kullanmayı seviyorsun ya), 160bin km'lik michelin. 3 te bir ömründe değiştiriyorsun lastiği, insanlara da saçma sapan 50bin önerisi veriyorsun, hiç yakıştıramadım mühendis bey.

yağın rengine göre değiştirmiyorum, ancak gelişmiş araçlardaki yağ ömrü ölçen sensörler yağın rengini de hesaba katmaktadır, yani yağın kirlendiğinin bir ölçütüdür renk, bunu unutma

10bin km'de hava filtresinde bir sorun göremiyorum diyorsan, gerçekten hayatın boyunca kaç tane 10bin km'de filtre gördün merak ediyorum. kaldı ki 20bin'de filtrenin tıkandığını görmedim demene yorum bile yapmıyorum

araban 226 bg olabilir. bu arabalardan anladığın anlamına gelmez. nice 500'lük cayenne'lerin içinde kadınlar gördüm, buji nedir bilmeyen herkes dalıyla ilgili konuşsun diyorsun, ne mühendisi olduğunu bilmiyorum ama ben kimya mühendisiyim, hani bu yağları üreten firmaların R&D'lerinde çalışan, yağı üreten, testlerde önlüklere boy gösteren isviçreli bilim adamları var ya, işte onlardan inşallah bana da branşınla ilgili konuş demezsin

ALLAHIM NEDEN BU İNSANLARI BENİM KARŞIMA ÇIKARTIYORSUN GİT UZMAN OLDUĞUN KONUDA YORUM YAP NİYE Mİ?

VERDİĞİN ADRESTEKİ LASTİK TRUCK NE DEMEK BİLİRMİSİN KAMYON DEMEK.VE BUNLAR PİKAPLARDADA KULLANILIR HIZ KODLARI ÇOK DÜŞÜK OLANLASTİKLERDİR OTOMOBİL LASTİKLERİ HIZ KODU genelde S VE T DEN BAŞLAR SENİN BAHSETTİĞİN HIZ YAPILAMAYAN LASTİKLERDİR ARAZİDE PİKAPTA KAMYONETTE VE KAMYONDA KULLANILIR KAMYON PİKAP OFF ROAD LASTİKLERİ OTOMOBİL LASTİKLERİ GİBİ YÜKSEK DEVİRLERE ÇIKAMADIĞI İÇİN OTOMOBİL LASTİKLERİNİN EN AZ 2-3 KATI DAHA FAZLA KM YAPAR BUNU TÜM OTOMOBİLDEN ANLAYANLAR BİLİR AMA KİMYA MÜH BİLMEYEBİLİR LÜTFEN SUS BEN KİMYA KONUSUNDA AHKAM KESİYORMUYUM. SENİ BLOKLUYORUM MUHATAP OLMAMAK İÇİN. LÜTFEN ANLADIĞIN KONULARDA YORUM YAP LÜTFENNNNNNNNN o CAYENNE İÇİNDE OLANLAR HİÇ OLMAZSA SENİN GİBİ KAMYON LASTİĞİNİ OTOMOBİL LASTİĞİYLE KIYASLAMIYOR :)
1.mil kullanmayı sevmem amerikan sitelerinden örnek verdiğim için yazdım
2.senden çok daha fazla filtre gördüğüm kesin 2 yıl servis müdürlüğü yaptım
3.dikkat edersen ben 50 binde yağ değiştirin demedim ben avrupadan örnek verip bizde 2-5 binde yağ değişimine yönlendirenleri kınadım.
4. sen mecliste uyuyupta uyanan ve ankaraya deniz istiyorum diyenlerdensin
5.sen güçlü otomobillerin yağlarından bahsettin bende ben biliyorum o arabaları bende kullanyorum dedim (işine geldiği gibi algılama)
6.2 yılda gördüğüm yağ,hava filltreleri emin ol senin gördüğünün en az 100 katıdır isviçreli bilim adamı
ADAMIN BİRİ SERVİS 10 40 YAĞ KOYDU ARACIM YAĞ EKSİLTTİ 5 30 KOYSA EKSİLTMEZDİ DER DİĞERİ KAMYON LASTİĞİYLE OTOMOBİL LASTİĞİNİN KM SİNİ KIYASLAR VE BUNLAR BİRDE HİÇ SIKILMADAN ANLAMADIĞI KONULARDA AHKAM KESER BİRDE YAZISINI OKUYUN KENDİNE İSVİÇRELİ BİLİM ADAMI DEMİŞ ÖZENDİĞİ TİPLEMEYE BAKIN ÇOK KOMİK YA :) BARİ BİR TÜRK MÜHENDİSİYİM DE İŞTE YAZISI
testlerde önlüklere boy gösteren isviçreli bilim adamları var ya, işte onlardan

< Bu mesaj bu kişi tarafından değiştirildi fsnn -- 4 Nisan 2011; 22:27:40 >

fsnn

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1195 Mesaj

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quote:

Orijinalden alıntı: vezir

peki bu konuda sıkıntınızı anladım.

ücüncü maddedeki gibi ayın yirmisinden sonra benim avukatımın ANkara'daki ofisinde buluşalım ancak parayı vereceğini kesinleştirmek için ikimizin de anlaşacağı bir konu lazım çek senet işlerini sevmem davalar yıllarca sürer. Siz parayı vermeye hazırsanız banka yolu ile gerisini hallederiz. Ama paranız gidince yüreğinize oturacak ve sonrasında sapıkça mailler falan gelmeye başlarsa bu konuları da benim çekincelerim olacağını unutmamalısın. Anlaşmaların hukuki yapılmasının temel bu tür riskleri olmadan enaza indirebilmektir. Yağda kabul etmesenizde, risk analizini sizin de kendiniz ve gidecek paranız söz konusunda olduğunda tedbir almanız manidar. Millet 50 milyarlık arabasına aynı konuyu düşününce tukaka oluyor.

quote:

Orijinalden alıntı: fsnn

Benim önerilerimi kabul etmezsin çünkü işine gelmez çünkü 41 Sayfadanda anlaşılacağı üzre bunu kabul ettiğin an yazdıklarının çoğunun yanlış olduğunuda kabul etmiş olacaksın
1.AVUKATINLA YOLLADIĞIN KİMLİK BİLGİLERİNİN SEN OLDUĞUNU NERDEN BİLECEĞİM
2.SEN ZATEN BENİM DENGİM OLAMAZSIN SEN HER SEFERİNDE SÖYLÜYORSUN
3.DRÜSTLK ABİDESİ VE OTOMOBİL UZMANININ FORMDAKİ KİŞİYLE AYNI OLDUĞUNU SORULARIMLA ANLAYIP PARAYI TAKTİM EDERİM YOKSA O MUHTEREM YÜZÜNE HASRET DEĞİLİM ÖYLE BEN AVUKATLA KİMLİK BİLGİLERİMİ YOLLARIM PARAYI VER OLDU BAŞKA.
BTÜN SÖYLEDİKLERİMİ BELGELERİM O YÜZDEN KONUYU SONLANDIRMADAN SÜZ SİZ OLUN 3.5.7.9 BİN KMDE ÖYLE HERKESİ YAĞ DRĞİŞİMİNE YÖNLENDİRMEYİN MİLLİ SERVET YAZIK.DÜRÜSTLÜK ABİDESİ OTOMOBİL UZMANI.

sen kendin olduğunu ispatladığın sürece sorun yok bende verecek 10 binlirada çok.
yalnız ben istemiyorum almıyacağımda bağışlarım ama 10 bin km dolmadan yağ değişim tavsiyesinde bulunduğun onlarca insan var ve 20 bin km de yağ bozulur değişmesi lazım dediğin
bende diyorumki 20 bin km de yağın bozulmadığını ispatlarsam üstelik bu bir yerli marka
10 binlirada onun için girelim söz mehmetçik vakfına bağışlıcam
yoksa kaç gündür neyi tartışıyoruz biz.
NEDEN ÇEKİNİYORSUN HANİ EN GEÇ 10 BİNDE DEĞİŞİRDİ

quote:

Bir yerde küçük adamların büyük gölgeleri oluşuyorsa, orada güneş batıyor demektir!

YAZIYA CEVABEN

SEN O KADAR BÜYÜK ADAMSINKİ GÖLGELERİN BİR YERLERE SIĞMIYOR. BURADA TÜM AMACIM BELGELERİYLE YAZDIKLARINI ÇÜRÜTMEK ÇÜNKÜ BEN BELGESİZ VE EMİN OLMADIĞIM HİÇBİR KONUDA YORUM YAPMAM. İŞTE O ZAMAN BURDAKİLERİN KARŞISINDA NASIL AHKAM KESECEKSİN MERAK EDİYORUM. BEN OLSAM FORMDA YAZMAYA UTANIRIM

< Bu mesaj bu kişi tarafından değiştirildi fsnn -- 4 Nisan 2011; 22:34:10 >

038poyraz

Yarbay

2455 Mesaj

Tüm Başarılarını Gör

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

quote:

Bir yerde küçük adamların büyük gölgeleri oluşuyorsa, orada güneş batıyor demektir!

Bu güzel sözü güneş batan yer olan bu forum için söylemiştim ,yani aslında gönderme yaptığım yer forum yöneticileri idi. Yine küçük adamlar bu işe alınmışlar.Ne küçüklüğün ne büyüklüğün önemi vardır sadece bilginin , görgünün , anlayışın , ahlakın , doğruları bulmak için çabanın bırakılmaması önemli olandır. Büyüklük küçüklük göreceli kavramlardır ,her bakış açısına göre farklı doğrular ve yanlışlar barındırabilir.

Bir bakış açısından tamamen doğru ve yadsılamayacak ölçümlerle geçerli olan bir durum diğer açıdan hatalı veya yanlış çıkabilcektir. Sizlerin de bir konuyu ölçerken söylenenleri sizin ulaşmak istediğiniz ve diğer açılara göre yorumlara kulak vermenizi öneririm.

yanlış anlaşılmasın diye anlatmak istediğim şeye bazı notlar düşmek istiyorum .Alınganlık olmasın diye

Yorumlarımızın ve değerlendirmelerimizin hepsi gölgelerdir. Bakış açısına göre değişebilir .Bakış açısını ise güneş belirler
bir yerde büyük gölgelerin oluşması için güneşin batışını beklemek gerekir ki gölgelerin boyuna önem verenler emellerine ulaşabilsinler.

Çamur atmak gölgelerin boyunu değiştirmez , sadece asıl olanı kirletir. Kirlilik temizlik sadece kirlenen için önemlidir. Gölgelere etkisi olmaz.Güneş bilgi kaynağı ise çamur atarak onu sıvayamazsınız . ''güneş balçıkla sıvanmaz'' sözünü bunun için ifade etmiştim.
Ama hedefiniz bilgiyi bulandırmak ve farklı sonuç çıkarmak ise, kişiye çamur atamıyorsanız önündeki pencereye çamur atarsınız hem etraf kirlenmez hem de pencere kirlidir diye kimse gocunmaz ama gölgelerin boyu uzar .Çünkü güneş değil ama pencere kirlendiyse ve birileri gölgeleri ölçüyor ise hedefine ulaşmış olur.
Bu mesajlar da yıllarca internette kalır ise birileri okur kendince yorumlar , kimin haklı olduğu değil güneşin parlaklığı hangi zaman ne kadarmış bilirler ve ülkemizin neden yozlaştığına dair bir daha mutlak fikirleri olur.

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

038poyraz

Yarbay

2455 Mesaj

Tüm Başarılarını Gör

Stranger

Yarbay

2597 Mesaj

Tüm Başarılarını Gör

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

biraz teknik olcak ama anlamayanlar için daha detaya girmem gerekiyor kusura bakmayın , eğitimin sonu yok ama almak isteyenler için geçerli maalesef . Böylesine kişiler oldukça yazasım gelmese de bilgi verilmesi gereken bir şeydir.Bu işten çok para da kazanılabilirmiş daha yeni farkediyorum ,ama emeğin karşılığını almam etik olmaz hele 50,000 TL . Ben yine yazacağımı yazayım bilenler anlar zaten !
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Particle counting is one of the most common oil analysis tests. It can be used to determine the cleanliness of new oil, identify dirt ingress, verify filter performance or indicate the onset of active machine wear. However, like most oil analysis tests, obtaining a representative sample is paramount to the accuracy of particle count data. With particle counting, this is particularly true, since in some instances where cleanliness targets are tight, one may be trying to identify fewer than 100 particles, which are similar in size to red blood cells, in every ml of fluid!

One of the most important, but often overlooked, key contributors to inaccurate particle count data is bottle cleanliness. Where target cleanliness levels are very tight, even the process of removing the cap from the sample bottle in a dusty environment may render the bottle unusable for particle counting. Despite this, very few sample bottle suppliers provide a certificate of inspection, verifying the cleanliness of new bottles. It is time for bottle producers, commercial laboratories and industrial end users to recognize the importance of sample bottle cleanliness and come together to develop an appropriate certification system for bottle cleanliness.

The True Cost of Unclean Bottles
The cost of unclean bottles is far more than the cost of a wasted bottle, which typically ranges from fifty cents to several dollars. Industrial users of oil analysis who are serious about their programs use results of tests such as particle counting as a basis for maintenance decisions. Therefore, the cost of an unclean bottle can be quite high.

A bottle causing a one- or two-range ISO code jump in a particle count may signal an alarm that results in significant investigation into a production process problem that never existed - a false positive. Maintenance or engineering resources are therefore wasted on an investigation that has no hope of providing value to the organization. Perhaps another sample is taken to verify the result. Resources are wasted in sample collection and testing. Time is wasted as the sample is turned around. If bottle cleanliness is wildly out of control (widely varying), there is no reason to believe the second test will provide more reliable data than the initial test.

Maintenance decisions, then, such as a filtration upgrade, fluid change or even overhaul, are based on a false alarm. The corrective action itself may have consequences that could threaten the system’s reliability.

Bottle contamination can also result in false negatives and potentially missed opportunities to take early preemptive action. Bottle contamination with excessive amounts of dust and other nonferrous debris could result in underreporting important wear-screening measures such as percent ferrous particles. In effect, lack of bottle cleanliness short-circuits the predictive and proactive maintenance processes.

Bottle Cleanliness Definition
Bottle cleanliness definitions currently used in industrial oil analysis originated in the fluid power research setting. These definitions focus on particles greater than 10 µm (Table 1).1

Even though tables that attempt to translate ISO 4406:99 particle counts into the number of particles greater than this size exist, it is clear that the particle size distribution will vary according to the process in which they are produced. It has been noted that some particle distributions, such as dusts, may be normal. Roll milling of larger particles in mechanical systems and filtration tend to skew this distribution toward the smaller end, producing a log of normal distribution. Over time, such a skewed distribution progresses and eventually approaches the Rossin Rammler distribution (Figure 1).

Figure 1. Natural Evolution of Particle Size Distributions from Large to Small Sizes.1

In the March-April 1999 issue of Practicing Oil Analysis magazine,

quote:

Jim Fitch proposed that a minimum acceptable signal-to-noise ratio (SNR) of 5:1 be used when selecting bottles for industrial oil analysis use.2 When industrial particle counts are performed using the ISO 4406:99 standard that identifies particles in ranges greater than four, greater than six and greater than 14 microns, how does one determine which bottles are clean enough for use based on cleanliness definitions focused at an entirely different size range?

Anyone who has attempted to rigorously establish the actual cleanliness of commercially available bottles knows the answer to that question is in effect irrelevant. Mass-produced bottles of the type commonly used for routine particle counting are not certified to any particular cleanliness level. At best, typical cleanliness levels are quoted. These levels, however, are hardly sufficient for most process critical applications.

Typical cleanliness levels are defined as the arithmetic mean of some sample population. Perhaps some analysis was done to establish a confidence interval for the actual average cleanliness of the underlying population assuming a roughly normal distribution with only one peak and tails that decay rapidly. Unfortunately, these assumptions may be entirely false. Data is distributed normally when the process producing it is completely in control; the variation that exists between bottles is caused only by random variations that have no assignable cause.

Is the production process that produces the bottles used by your facility in control? The only way to determine if the bottle production process is in control is with rigorous statistical tests.

The Need for a New Guideline
ISO 3722, the primary standard that addresses methods for establishing bottle cleanliness, is extremely rigorous. While appropriate for research laboratory use, the testing requirements are too onerous for broad application to most industrial oil analysis applications. The number of samples that must be evaluated from a production run is so great that the expense of certification makes them too costly for routine analysis.

A new guideline for industrial used oil analysis particle counting bottle cleanliness classification is needed. The guideline should be robust and sensitive to variations in particle size distribution so it will apply equally to any production process. It should also be clear to the end user which bottles can be used effectively in each particular application.

Bottle Costs
Users, however, must be prepared to pay more for certified bottles. Testing each production run will always involve significant expenses to bottle manufacturers, resulting in high bottle prices, especially when compared to the prices at which bottles are currently sold. Additional expense will be required to correct production deficiencies. Bottle producers must be able to justify the cost of producing a bottle with verifiable and improved quality. Customers will benefit if they recognize and demonstrate a willingness to pay for superior products.

Recommendations
Industrial users are primarily concerned with target particle counts as defined by ISO 4406:99. Because particle size distributions vary depending upon the process that produces them, it is logical to think that bottles should be certified at all three size ranges rather than just at 10 microns, which does not correspond to ISO 4406:99 range numbers.

Several factors must be considered for the portion of production runs that are in control:

•First, what is an acceptable cleanliness level for particle counting at certain range numbers?
•What signal-to-noise ratios are commonly applied?
•Are the signal-to-noise ratios universal?
•Should a standard be established

to reference actual counts or acceptable target levels assuming a signal-to-noise ratio? (A balance between flexibility in the standard’s application and its ease of use must be struck.)

•What level of user sophistication should be assumed?
Other questions that may come up include: How much of each production run is potentially defective? And, can the quality of bottles produced while the process was out of control be described? Studies conducted by Noria indicate that even production runs that achieve low average contamination levels produce a much higher proportion of defectives (outliers) than a strictly normal distribution would produce. This indicates that the production process is not consistent, and that the actual defect rate should be quantified.

By definition, it is impossible to predict with an economical sample size just how contaminated defective bottles may be, however an attempt can be made to quantify what proportion of the overall production may be defective. Why is this important? If most bottles are clean enough to produce a signal-to-noise ratio that does not result in false alarms for high fluid particle count, then those that are defective, if sufficiently deviant, would produce a false alarm.

With high defect rates, even a retest could confirm an errant result. How should sufficiently deviant be defined? What is an acceptable false alarm rate? Are different classes of users likely to define these differently?

Will tiered certification allow most users to buy relatively inexpensive bottles that meet their needs while still allowing the standard to produce better bottles at an appropriate incremental price? An investigation into the statistics required to assess bottle cleanliness indicates that the greater the level of confidence in bottle cleanliness, the more onerous (and expensive) the testing process becomes. Cost and benefits must be rationally equated. The system need not be a pass/fail endeavor. Production runs could be certified to the highest level possible for the testing protocol, or to lower levels depending upon the actual performance witnessed in testing.

Author’s Note
Further discussion of this issue is warranted between all stakeholders. Several conversations among Noria consultants failed to end in a consensus of what an appropriate certification system might look like. The author will present a paper at Lubrication Excellence 2003 to spark discussion among bottle producers, commercial laboratories and industrial end users. The technical paper will focus on the statistics involved in determining an appropriate testing protocol. The author also plans to facilitate a discussion between all interested stakeholders in an attempt to start moving the industry toward some consensus. Hopefully such discussions will be echoed at International Council for Machinery Lubrication (ICML) and other standards-writing organizations until this issue is resolved.

If you would like more information on how to certify bottles, be sure to attend Lubrication Excellence 2003. Noria looks forward to seeing you there and hearing your opinions.

References

1.Fitch, E. (1992), Proactive Maintenance For Mechanical Systems. Stillwater, Oklahoma: FES Inc.
2.Fitch, J. (1999, March-April), The Influence of Bottle Cleanliness and Sample Agitation. Practicing Oil Analysis. pp. 15-18.

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

peki hangi parametreler gözlemlenerek bir yağın değiştirilip değiştirilmesi hakkında YORUM yapılabilir

Lubricant contamination monitoring
A. Particle contamination
1. Methods and units for measuring particle contamination
a) ISO solid contamination code (ISO 4406)
b) Optical particle counting (ISO 11500, ISO 11171)
c) Pore block particle counting
2. Effects on the lubricant
3. Effects on the machine
B. Moisture contamination
1. States of coexistence of water in oil
2. Methods and units for measuring moisture contamination
a) Crackle test
b) FTIR analysis
c) Co-distillation
d) Karl Fischer titration (ASTM D1744 & D6304)
3. Water demulsibility
a) Test methods and units (ASTM D1401 & 2711)
b) Causes of poor water demulsibility
4. Effects of water contamination on the lubricant
5. Effects of water contamination on the machine

C. Glycol coolant contamination
1. Methods and units for measuring glycol contamination
a) Elemental spectroscopy
b) FTIR analysis
c) Schiff's Reagent (ASTM D2982)
2. Effects on the lubricant
3. Effects on the machine
D. Soot contamination
1. Methods and units for measuring soot contamination
a) Thermogravimetric analysis (TGA) - (ASTM D5967-A4)
b) FTIR analysis
c) Pentane Insolubles (ASTM D893)
2. Effects on the lubricant
3. Effects on the machine

E. Fuel contamination (fuel dilution in oil)
1. Methods and units for measuring fuel contamination
a) Viscosity effects (ASTM D445)
b) FTIR analysis
c) Flash point test (ASTM D92, D93 & D3828)
d) Gas chromatography (ASTM D3524)
2. Effects on the lubricant
3. Effects on the machine

F. Air contamination (air in oil)
1. States of coexistence
2. Methods for assessing air contamination
a) Air release characteristics (ASTM D3427)
b) Foam stability characteristics (ASTM D892)
3. Effects on the lubricant
4. Effects on the machine

< Bu mesaj bu kişi tarafından değiştirildi vezir -- 5 Nisan 2011; 16:42:42 >

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

Why do synthetic oils often last longer? Heat and oxidation are the primary reasons for oil break down. Petroleum-based lubricants are mixtures of several sizes of hydrocarbon molecules, sulphur, paraffins, salts and metals. With different evaporation, oxygenation and burn points for each size and type of molecule, the refined petroleum-based oils start changing to an extent the moment you start your car.

In time, a lubricant will have a diminished ability to perform its job, which is to lubricate metal-to-metal contact surfaces in machinery and to transfer heat away from the area being lubricated. The diminished ability to lubricate increases as the molecules of various size and weight are consumed by evaporation and oxidation. Lubrication ability may continue to diminish as these various molecules interact with the blow-by gases and other contaminants in the engine environment. Additives are used to control acid, stabilize viscosity, and keep soot in suspension. The additives are typically consumed as they do their job. Therefore, in many cases, but not all cases oil needs to be changed at familiar intervals of 3,000 or 5,000 miles.

Synthetics are more uniform. Synthetic oils are much more thermally stable as a result of this uniformity. For instance, synthetic oils need lessVI improver additive to keep their viscosity stable. Synthetic oil additives may be higher quality or at least work longer.

Synthetics may have better viscosity film strength than petroleum stocks at elevated temperatures (greater than 176°F/80°C). Film strength indicates a lubricant’s ability to occupy the space between two metal surfaces under pressure or heat. This is the fundamental reason for lubrication, to hang in there and do the job. Higher film strength was one of the factors that changed my mind about changing oil.

However the final straw is the fact that many synthetics have a much higher base number (BN) retention than petroleum-based formulations. The BN is contributed by overbase additives such as detergents and is a measure of a lubricant’s ability to neutralize acid. The longer a lubricant can resist turning to acid, the longer it can be used. This fact, along with the decreasing cost differential of the two lubricants, is reason enough to use synthetics

1.Ramsey, P. “Multigrade Oil - To Use or Not To Use.” Machinery Lubrication, July-August 2001.
2.Ramsey, P. “A Breath of Fresh Air.” Machinery Lubrication, September-October 2001.

< Bu mesaj bu kişi tarafından değiştirildi vezir -- 5 Nisan 2011; 17:08:40 >

vezir

Otomobil Uzmanı

11087 Mesaj

Tüm Başarılarını Gör

gelelim işin teknik olarak nasıl hesaplanacağına

It is interesting to me that owners of many later model cars will find 10W-30 suggested in their manuals. I’ll be honest: 10W scares me. The 5W-30 suggested by some also concerns me. In the southern part of the country, we don’t need 10W oils. Decreased friction of 10W and 5W oils does mean slightly better mileage. But I wonder if it isn’t suggested for reasons of meeting corporate average fuel economy (CAFE) standards. This government regulation demands that vehicles meet increasing mileage levels. However, the question must be raised: Are we sacrificing engine life for slightly higher mileage to meet a government regulation? How much engine life is sacrificed? Is it cost-effective when compared to savings on gasoline costing $1.00 and $2.00 per gallon?

quote:

burada bizim ülkemizdeki yakıt fiyatlarının yüksek olacağını göz önüne alarak formuldeki değerleri buna göre brim fiyat olarak ele almamız gerekli .Aynı şekilde ülkemizde tam sentetik fiyatları da anormal yüksek ABD ye göre herneyse ,

Your SAE 10W oil is not your father’s 10W oil. Consider the following changes in lubricant formulation that have occurred during the past 20 years:

A. Modern PAO synthetic base oils and highly refined mineral oils have
naturally high viscosity indices (120 to 150 vs. 80 to 100 for older oils). In other words, a modern oil’s viscosity changes less for a given change in temperature, so it provides more protection at higher temperature, even though the oil is a lower viscosity grade.

B. Antiwear additives are better than ever. They are more stable and provide better boundary (surface to surface contact) protection than older technology additives.

C. Viscosity index (VI) improver technology has improved. The modern additives are much more shear-stable than older VI additives (the molecules resist being chopped up in the engine). Plus, because of the use of base oils with a higher natural VI, less of this additive is required.

Not only are lubricants better, but engines are more reliable too. Designs are better, machining tolerances are tighter and more consistent, fuel injection and electronic ignition have optimized combustion, materials technology is more precise - all of which add up to increased life and fewer problems during the typical service period. Do you remember when 100,000 miles was good life out of a vehicle? Today, 150,000 miles and more is the norm, and we achieve this service life with a lot less maintenance. We may reminisce about how well-built cars were in the “good old days,” but if one looks objectively at reliability, the good old days are now (and getting better).

Another point is that most people don’t need more engine life from the typical consumer vehicle. While exceptions exist, consumer vehicles have a typical life of 12 years and 150,000 miles. Beyond this time frame, the following problems begin to arise:

A. Auxiliary system maintenance and nuisance failures become excessive.

B. The vehicle becomes an environmental nuisance due to leakage, reduced combustion efficiency and outdated (or out-of-service) emission control systems.

C. The vehicle’s styling becomes dated (some consumers are very style-conscious about their vehicles).

But the question about viscosity selection really comes down to dollars and cents. To justify using higher viscosity oil at the expense of fuel economy, the following statement must be true:

Rc> (FPV / PEF x PLE)

Where:
RC = Present value cost (today’s dollars) of an engine rebuild
FPV = Present value of fuel savings attributed to using low viscosity oil
PEF = Probability that the engine will fail before reaching the end of its required service life
PLE = Probability that engine failure could have been avoided by using high viscosity oil

During its life, the typical car burns between 6,000 and 7,500 gallons of fuel. Using the model above, let’s determine the rebuild cost required to justify a decision to use higher viscosity oil to avoid an engine failure.

Assumptions:
FPV = $210, assuming a 3 percent reduction on 7,000 gallons purchased at one dollar per gallon (21.4 mpg)
PEF = 10 percent chance that the engine will fail before reaching 150,000 miles, our required life
PLE = 20 percent chance that a higher viscosity oil would have avoided the failure

RC = $210/(0.10 X 0.20)
= $210/0.02
= $10,500

So, the present value of an engine rebuild must exceed $10,500 (using my assumptions) to justify the use of higher viscosity oil, which is very high for a consumer vehicle. The calculation can be turned around to determine how much improvement in fuel economy is required to justify assumption of the risk of engine failure . . . all depending, of course, upon your assumptions about the risk of engine failure, and the likelihood that higher viscosity oil will reduce that risk.

For modern vehicles, the dollars and cents just don’t add up. While the life cycle fuel savings may seem small, they are large compared to the risk-adjusted cost of an engine rebuild. There are intangibles to consider as well, like the feeling you get from doing your part to reduce our impact on the environment and dependence upon fossil fuel.

< Bu mesaj bu kişi tarafından değiştirildi vezir -- 5 Nisan 2011; 17:33:59 >

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