(X204): Análise laboratorial de troca de óleo motor feita em 2010 - inglês

Navegando no Fórum MBWorld, veja essa postagem que encontrei de 2010, onde um proprietário fez uma análise laboratorial do óleo de motor:

http://mbworld.org/forums/glk-class-x204/360282-glk-oil-analysis-test-comparison.html

"My buddy just had his GLK oil analyzed by Blackstone Labs (All of us use these guys: http://www.blackstone-labs.com/about-us.php) at around 9700 miles on the OD. (Remember I argued against waiting for the factory 10K recommended oil change interval. As stated in my earliar post, I changed my wife’s GLK oil and filter at 1K, 3K and then every 5K. I’m sorry to report that these test result confirm what I was trying to warn all my fellow GLK owners about. Those who refused to heed my warning should have at least given me the benefit of the doubt.) 

His Analysis Basically Says: "As this is the first oil change, higher than normal wear levels have been detected primarily due to the internal parts getting to know one another during the first 10 thousand mile interval. We will probably see the results of this wear in proper phase for the next 3-4 oil changes. Universal averages show higher than typical wear levels for this type of engine after about 5400 miles on the oil. (This basically means that as the oil becomes contaminated with metal over time, the oil becomes more abrasive which adds even more metal to the oil.)

The TBN (Total Base Number) was a STRONG 2.9 showing plenty of active additives still left in the blend, less than 1.0 is too low. (This confirms that the cleaning additives are still present, but the oil was still filled with worn metal, the primary reason to change new engine oils sooner rather than later, even if it is a synthetic.) The air and oil filters are working well." 

Recommendations: "For now try a couple of 5K oil changes until all the metal abrasives have been washed out.”

Elements PPM that were hi-lighted: 
Aluminum 9 - (Wow! The average is 3) 
Iron 108 - (16 is average) (Wow!!!!)
Copper 38 - (6 is average) (Wow again)
silicone 51 - (7 is average) (And Again!) 

Properties: 
SUS viscosity @ 210*F 65.7 
CST viscosity @100*F 11.79 
Fuel <.5% - 2.0 
Antifreeze 0
Water 0 -<.1
Insoluble’s .3% - <.6% 
TBN 2.9 

Now check out this comparison test:

http://www.animegame.com/cars/Oil%20Tests.pdf ."

É bom lembrar que, em tese, a gasolina americana não tem os riscos de fraude/adulteração que temos por aqui.

E esse último link tem uma aferição comparativa entre vários óleos/fabricantes, feito na época.

Mas o site oficial da SAE, gera polêmica:

http://papers.sae.org/2007-01-4133/

"Engine oils are subjected to a series of industry standard engine dynamometer tests to measure their wear protection capability, sludge and varnish formation tendencies, and fuel efficiency among several other performance attributes before they are approved for use in customer engines. However, these performance attributes are measured at the end of tests and therefore, do not provide any information on how the properties have changed during the tests. In one of our previous studies it was observed that engine oil samples collected from fleet vehicles after 12,000 mile drain interval showed 10-15 % lower friction and more importantly, an order of magnitude lower wear rate than those of fresh oils. It was also observed that the composition of the tribochemical films formed was quite different on the surface tested with the drain oils from those formed with fresh oils. The objective of this investigation is to demonstrate how the friction and wear performance changed with oil drain intervals. A fleet of three vehicles was run in Las Vegas and oil samples were collected at various drain intervals from 3000 miles to 15000 miles. As in the previous study, the results showed that the aged engine oils provide lower friction and much improved wear protection capability. These improvements were observed as early as the 3000 mile drain interval and continued to the 15000 mile drain interval. The composition of tribochemical films formed on the surface with the 3000 mile drain interval is similar to that formed with the 12000 mile drain interval as seen before. These findings could be an enabler for achieving longer drain interval although several other factors must to be considered."

Depois dessa, só comprova o que meus colegas da pesquisa de petróleo falam e ajuda ainda mais a eu continuar trocando o óleo a cada 5000Kms.
Obrigado Aderson!
Abraços,
Sergio