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Transmission fluid black as night with only 25K miles.

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Old 04-28-14, 01:33 PM   #31
jzwu
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I always use OEM oil filters, which should have the capacity to filter out contaminants per manufacturer's recommended change intervals.

As for "dirty oil", it is the most widely used misconception. What does "dirty" mean? Because it looks dark/black and smells bad? Or, you feel that the oil is dirty?

The only scientific way to determine is to do lab analysis of the oil. As I mentioned earlier, the results have consistently shown 10k miles "dirty oil" is not actually dirty by scientific analysis of contaminants and usable additives, etc.

Touchy feely is often wrong.
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Old 04-28-14, 06:08 PM   #32
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Originally Posted by jzwu View Post
Using fluid color/small for assessment is not very scientific. Do you agree? That's the rudimentary method used decades ago on the fluids belonging to that era.

Has anyone smelled the new ATF? It smells really bad when brand new. Color alone cannot be used to assess how usable the fluid is, either.

Blackstone lab has done many engine oil analyses on Mobil 1 synthetic oils from many different owners. I have never seen one report stating that the oil was bad within 10k miles. Changing synthetic engine oil at 5k miles is a total waste.

And Yes, I do engine oil change, ATF change, differential oil change, coolant change and spark plug change, among other car work, myself indeed.
You do seem to have a problem with reading comprehension. My words in my first post were “Initial guide” with the word initial underlined (that mean special emphasis). Examining the ATF color, blotting a paper towel with fluid (looking for pattern spread to indicate excessive oxidation) and smelling the fluid to see if the fluid smells burnt are universally (emphasis here again) used by auto shops the world over.

Apparently you haven’t looked at many Blackstone reports either. The additives in oil are for the most part sacrificial. If brand new oil is added to a brand new engine the drop in additives (commonly referred to and measured as the TBN or total base number) is fairly linear as the oil ages. However, if new oil is placed in an older engine (especially one that has not been well maintained), the drop in TBN in the first few hours of operation is dramatic as the additives sacrifice themselves against the existing sludge and debris in the engine.

Plenty of report exist showing additives used up well before 10K miles with synthetic oil. It is a common misnomer that synthetic oil additives last much longer than conventional oil additives. While some (like viscosity index improvers in dino oi) are not needed in synthetic, many of the additives are very similar or exactly the same. While synthetic base stock withstands heat better, most additives in synthetic oil are chewed up at the same rate by acid, water, antifreeze and rust.

Being more expensive, synthetic oils have traditionally been sold as lasting longer than dino oil, and while to an extent that is true, by far the biggest advantage to synthetic base stock oils is their ability to withstand high heat while still maintaining a hydrodynamic film in large bearing surfaces, and their cold pour point characteristics which means engines receive relatively fast lubrication at -20F. These two characteristics alone dramatically reduce engine wear and extend engine life.

When I use Blackstone I am not looking to extend my oil changes, but for signs of excessive metals, fuel or antifreeze, suggesting either excessive journal bearing wear or early stages of gasket failure.

For my BMW, my last Blackstone report was with 5197 miles on Mobil 1 0W-40. TBN was 3.2 (objective is to keep it above 1.0) with no excessive metals and no measureable fuel or antifreeze. The comment from Blackstone was to try extending the oil drain interval to 7000 miles the next time.

For my SC430, the last Blackstone report was with 5333 miles on Mobil 1 0W-40. TBN was 2.8, metals were good and fuel, water and antifreeze were all zero. As expected the kinematic viscosity of the SC430 sample at 100C was slightly higher than the BMW, as my wife doesn’t drive the SC430 nearly as hard as I do the BMW. The comment from Blackstone was that there was still active additives left and to try and extend to 7000 miles.

Changing your oil while the additives are still present is the whole idea!!! Could I extend my oil changes to 7K or even 10K? Maybe. But exactly when does the TBN go under 1.0? I simply don’t have the time to mess with it, and I understand the effects enough (I am a graduate engineer) to know I don’t want to guess and be wrong. The savings in extending my oil changes would be the cost of one cup of Starbuck’s coffee per week! Really? I couldn’t care less.

Glad to hear that at least you do your own fluid changes. Now read some more!
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Old 04-28-14, 09:07 PM   #33
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If you believe and insist on your own assessment, I don't think anyone can persuade you in any other way. And that's fine with me.

I know BMW, MB and Porsche all recommend the synthetic oil change interval on their cars at 10k miles for normal driving (which fits most of us).

My old 2004 Toyota Sienna van has a 7,500 miles change interval for conventional oil. I owned it for 10 years and 130k miles since new and changed with conventional oil every 7,500 miles. It still ran like new without any sign of engine issues when I sold it. Now I bought a new 2014 Sienna van and its synthetic oil change interval is 10k miles recommended by Toyota.

I just hope that these four car makers (and many others) are not wrong in their oil change recommendation. :-)
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Old 04-30-14, 04:58 AM   #34
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Originally Posted by sorka View Post
My 2007 has 25K miles. I did a trans drain and fill today. The fluid that came out was black as black can be.

FYI for anyone thinking it's really ok to to go "lifetime" on the same fluid let alone 100K.

Click the image to open in full size.
Wow, that looks nasty. All the Lexus products I've owned always had red fluid after 100,000 miles, good luck bro.
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Old 05-01-14, 12:07 AM   #35
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Originally Posted by tromly View Post
Wow, that looks nasty. All the Lexus products I've owned always had red fluid after 100,000 miles, good luck bro.
Which vehicles have you owned with sealed transmissions that took ATF WS that had a red color after 100K on the original factory fluid?

There's nothing wrong with my transmission and it will most likely stay that way because I'm not going to be stupid and try to run atf for 100K miles.
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Old 05-01-14, 12:07 AM
 
 
 
 
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2007, 2008, atf, bad, black, check, fluid, forum, paper, prius, sienna, towel, trans, turns, ws

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