General observations and questions on recent UOAs

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777
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Herndon, VA
Greetings all, I have performed hundreds of UOAs in the past 35 years, and some recent observations I have noted I would like to get the group's reaction to. 1) Comparing VOAs and UOAs using Amsoil Signature series, I have noted that the additive Boron seems to get "Used Up" over the interval of an oil change. Yet other additives seem to stay constant. Why? Anyone have an explanation? Is the amount of the decrease in Boron compared to VOA levels of any use in determining when the oil is exhausted? 2) I have heard others note this observation, and never really believed it until I experienced it myself. A couple years ago, I switched all my vehicles from Mobil 1 AFE or EP, to Amsoil signature series. On BOTH of my Tundras, the vehicles initially consumed oil at the rate of about one quart in 5,000 miles, which neither vehicle ever did before. Yet, after a few oil changes, this consumption stopped, and after even 10K miles, I don't need to add any oil. Anyone have an explanation for this? I can't think of a reason other than coincidence. 3) NONE of my Toyota vehicles have EVER had a significant amount of lead in their UOAs. Is Toyota not using lead in Bearings anymore? I'll probably come up with more questions, but I'd like to toss these out initially. Thoughts?
 
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693
Location
PA
I really have no experience with this sort of thing compared to almost anybody here my engineering background is in electronics not mechanical or chemical, but I'll take a shot : Its my understanding that Boron is in part for anti-corrosion and also an anti-oxidant, that being said MAYBE with the newer engines (mostly alloy) there is higher rate of oxidation and corrosion therefore the boron is being used more to combat the two...... I'm sure someone will come along and prove this theory wrong.I have noticed this as-well. I have also been trying to find Ford 4.0 UOA's and THOUGHT that I found a trend of mid to upper ppm of boron along with higher iron.....than I found more UOA's to disprove that.
 
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11,374
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Florida, Cape Coral
When changing brands of oil, increased consumption is often noted. It may be that the engine needs to "re-breakin" at some level. The reason I don't arbitrary change brands unless I have a good reason. Ed
 
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147
Location
Ft. Collins
Originally Posted By: btanchors
Greetings all, 3) NONE of my Toyota vehicles have EVER had a significant amount of lead in their UOAs. Is Toyota not using lead in Bearings anymore?
Even in older Toyotas, there was probably more aluminum and or tin and only a small amount of lead in the top layer of the bearing shells. Currently, lead has fallen out of favor, possibly because of fatigue resistance of lead-free methods. If you look at the last page of: http://www.federalmogul.com/en-US/Media/Documents/CrankshaftbearingsMTZ122010.pdf ... you'll see the current popular options for the top layers, and none have lead.
 
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12
Location
WA
Regarding question #1 - Boron is at high risk for depletion due to water washing and rubbing contact. "Is the amount of the decrease in Boron compared to VOA levels of any use in determining when the oil is exhausted?" Absolutely - Increase the frequency of your oil changes. You may be experiencing a chemical-mechanical reaction between two surfaces,soot. Soot has an original size of 0.01 to 0.05 microns but agglomerates to form larger particles. An oil’s ability to disperse soot is critical to preventing soot-polishing wear caused by the effects of soot on the oil’s anti-wear additives.
 

btanchors

Thread starter
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777
Location
Herndon, VA
Bassnjunky - I don't understand what you are saying in the last sentence of the first paragraph. Are you saying the oil should be condemned when there is a detectable decrease in Boron levels? Or does it have to decline by a certain amount? Is there a rule of thumb (percentage, a raw ppm number, or whatever) as to when the Boron level by itself would suggest the oil should be condemned/changed?
 
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