First Black Stone report results in! UPDATE: *3nd Report in!*

[Exclusivs]

Got my Blackstone report back today on the car. First one I've done, let me know what you guys think. Car is 2009 N/A with 14,000 miles on it today. 93 Mobil 1 octane used when living on the East Coast, now 91 Chevron here in Arizona. Oil has always been Castrol 10W-60. Oil sample was taken after 7000 miles. Will now decrease that to 5000.

[Thik]

Why decrease to 5,000k when 7,000k looks fine?

[Exclusivs]

Originally Posted by Thik

Why decrease to 5,000k when 7,000k looks fine?

Might get better numbers on 5k intervals?

[M3PO]

I agree that you should stay at 7K miles. Those numbers look fine. Sure, the numbers will be lower if you go to 5K intervals, because you drove less miles. But in the end the only number that's lower that makes any difference will be your account balance.

[Exclusivs]

Originally Posted by M3PO

I agree that you should stay at 7K miles. Those numbers look fine. Sure, the numbers will be lower if you go to 5K intervals, because you drove less miles. But in the end the only number that's lower that makes any difference will be your account balance.

Agreed. Spoke w/ Blackstone this morning. They said go on a 7k change next time to also be able to compare apples to apples on next analysis.

Guess the bill is clear on a healthy S65?

[Exclusivs]

Second Report Results just in!

[BobS]

Cool.. mine show the same at 51k miles and supercharged

[Dolo_]

See this was exactly what I want talking about in another oil analysis thread. Multiple reports need to be taken to get a good trend and see how the motors health actually is. This is perfect, the more the better honestly then you get a good view as long as you do this at regular intervals.

Part of my job is oil analysis on aircraft engines and we use the same tables as Blackstone. The principles are the same and a trend has to be made to get an idea of what's going on. So OP keep it up and keep us posted. This is actually really good info just with you having more than one sample analysis. One sample won't tell you anything

[Exclusivs]

IMO - this is the only valid way to do it.

I will continue to do this for the life of the car under my ownership.

All in all very happy I got back a good second report (though I didn't expect different).

[Exclusivs]

3rd report in!

All good news here!

She's a keeper

[Exclusivs]

4th Blackstone Report in

All looking good

[dparm]

Pay for TBN and TAN next time.

[Exclusivs]

Originally Posted by dparm

Pay for TBN and TAN next time.

For reasons of ?

[dparm]

Originally Posted by Exclusivs

For reasons of ?

Helps establish a good change interval, shows if the reserve alkalinity is depleted, shows if the oil is turning acidic, etc.

[Exclusivs]

With an extremely busy last couple of months split between work, travel, and well...life, have admittedly not been as actively posting much. But here are my last TWO oil analysis from Blackstone. TBN and TAN taken as well on last 2 per recommendation of dparm. Nice extra little data point from those on the analysis - and I never mind nerding out on these types of things. Thanks Blackstone Laboratories for doing what you do!

P.S: For some reason I'm not allowed to edit the title of thread to reflect.

[dparm]

I don't see the TAN indicated on those reports -- only TBN.

[Ximian]

Blackstone doesn’t give you the option to have TAN measured for engine oil. I think they only do it for hydraulic and gear oil.

[anerbe]

If you scale your results to a 7Kmi interval (times your 2k mi metal values by 3.5), would this show trending of higher copper and iron/aluminum?

Just curious if the low mile OCI could be masking a potential increase in metal wear.

[dparm]

Originally Posted by Ximian

Blackstone doesn’t give you the option to have TAN measured for engine oil. I think they only do it for hydraulic and gear oil.

They absolutely can measure TAN for motor oil. I've been getting it on every analysis for years. You have to ask for it and pay an extra $10.

[Exclusivs]

Originally Posted by dparm

I don't see the TAN indicated on those reports -- only TBN.

Originally Posted by dparm

They absolutely can measure TAN for motor oil. I've been getting it on every analysis for years. You have to ask for it and pay an extra $10.

Inquired with Blackstone about TAN testing long ago - this was their direct response :

"We'll certainly do both the TAN and TBN tests for you if you want, but in our opinion, the TBN is by far the more useful of the two when it comes to engine oil.

The TBN (Total Base Number) measures the reserve alkalinity in the oil, or basically, how much capacity the oil has left to neutralize acids. The TAN (Total Acid Number) is essentially the opposite... it measures the level of acidity in the oil. The TBN starts high in new oil, and then drops over time. The TAN should start low, and then increases over time. Some people say that the point at which the TAN is higher than the TBN is the point at which you should change the oil, and that may be true for certain types of engines and certain types of oil, but we don't really hold to that in most cases. As long as the TBN is above 0.0, that tells us that the oil still has some capacity to neutralize acid, and as long as the TBN is above 1.0, there's probably enough active additive still present that you could run the oil longer.

Some types of oil will start with a TAN reading above 1.0, but that doesn't mean that the oil itself is acidic. An increase over time is normal, but even a TAN of 3.0 or 4.0 wouldn't be enough for us to say that the oil is too acidic, especially if everything else looks good. There's just not a useful benchmark for when a TAN reading becomes a problem, so that's why we say it doesn't give as much useful information as a TBN.

Again, we're happy to run both tests if you want, and if you monitor the results of both tests over several samples, it's possible that the trends could be meaningful. But in terms of what we can tell you with each individual test, I'd keep the extra $10 and just get the TBN if I were you. "

[Exclusivs]

Originally Posted by anerbe

If you scale your results to a 7Kmi interval (times your 2k mi metal values by 3.5), would this show trending of higher copper and iron/aluminum?

Just curious if the low mile OCI could be masking a potential increase in metal wear.

With respect to 'scaling' logic says theres no accurate way to do, or predict this. Think about it; if you consume the same amount of food over a steady period to know your 'normal' weight - then one day decide to go off the deep end and gorge yourself with fast food and junk food..chances are the next day or 2 you will be heavier.

Same thing with the engine in these cars : if 1 decides they want to take car out on a cold morning and bang out some 8k red line pulls..something tells me there will be an elevation in wear metals.

[dparm]

Originally Posted by Exclusivs

Inquired with Blackstone about TAN testing long ago - this was their direct response :

"We'll certainly do both the TAN and TBN tests for you if you want, but in our opinion, the TBN is by far the more useful of the two when it comes to engine oil.

The TBN (Total Base Number) measures the reserve alkalinity in the oil, or basically, how much capacity the oil has left to neutralize acids. The TAN (Total Acid Number) is essentially the opposite... it measures the level of acidity in the oil. The TBN starts high in new oil, and then drops over time. The TAN should start low, and then increases over time. Some people say that the point at which the TAN is higher than the TBN is the point at which you should change the oil, and that may be true for certain types of engines and certain types of oil, but we don't really hold to that in most cases. As long as the TBN is above 0.0, that tells us that the oil still has some capacity to neutralize acid, and as long as the TBN is above 1.0, there's probably enough active additive still present that you could run the oil longer.

Some types of oil will start with a TAN reading above 1.0, but that doesn't mean that the oil itself is acidic. An increase over time is normal, but even a TAN of 3.0 or 4.0 wouldn't be enough for us to say that the oil is too acidic, especially if everything else looks good. There's just not a useful benchmark for when a TAN reading becomes a problem, so that's why we say it doesn't give as much useful information as a TBN.

Again, we're happy to run both tests if you want, and if you monitor the results of both tests over several samples, it's possible that the trends could be meaningful. But in terms of what we can tell you with each individual test, I'd keep the extra $10 and just get the TBN if I were you. "

This has been talked about extensively at BITOG. It is true that TBN is the more useful number, but the value comes in comparing starting TBN and starting TAN to ending TBN and ending TAN. Hence the value of getting a virgin oil analysis (or finding someone else who already did it).

The TAN to TBN ratio is basically what's indicating if the oil has turned acidic. If you only pay for TBN, you're only getting half the picture. You could get a TBN of 5 and think that the oil could've stayed in longer -- without realizing that the TAN had risen to 7 and turned the oil acidic. This is especially a concern if you aren't driving the car a lot and/or have tons of short trips, and the oil has been in the car for a long time.

For $10, I'll sleep better knowing the oil hadn't gone too acidic.