[Shop-talk] Oil analysis - Blackstone

[Todd Walke]

You wrote:

>Anyone else using Blackstone labs or other services for oil & fluid 
>analysis?  I sent off samples of oil and ATF from my mom's 2003 BMW 
>530.  She's been going by the dashboard "service soon" indicator, which 
>works out to over 15,000 miles between oil changes (!!!)  BMW also claims 
>the ATF and differential oil are "lifetime" durable.  I called bull on 
>that, and have started doing oil changes for her, and swapped the 
>ATF.  Sent samples to Blackstone, actually hoping for some bad news to 
>shock & awe her into taking better care of the thing (she intends to keep 
>driving it for a good while.)
>
>Amazingly the 17,500 mile oil and 89,000 ATF came back with pretty good 
>results.  Anyone else using Blackstone?  Wanna trade notes?  Don't think 
>attachments will go through the list server, but if you're interested, I 
>can send you the reports off-list, or post on the web.

         I've used Blackstone for 12 reports over 120,000 miles in the 
TDI.  Blackstone is very well respected in the TDI world.

         VW specs out 10,000 miles oil changes for my TDI.  Synthetic oils 
required.  I was used to changing oil at 5,000 (with synthetic) or 2,500 
(with dino oil) in my old Golf, so I felt a bit nervous about the longer 
interval.
         On my first UOA I paid the extra $10 for a TBN (Total Base Number) 
test.  Oil turns acidic over time, so there is a additive in the oil that 
is a base to counteract that.  The TBN on virgin oil will generally be 
around 10-13 or so.  The TBN number drops as the additive is "used up".  If 
the TBN number falls to zero, the acids will cause excessive wear.
         My TBN test showed the TBN after 10,000 miles was 2.1 - therefore 
the additive package was still functioning.  Wear metals were well within spec.
         Many TDI owners are running extended oil change intervals, up to 
15,000 and more.  Some sample periodically and change when the test shows a 
need.  Others retrofit the European oil sensor, activate the "service" 
light on the dash and use that as a guide.

         Bottom line, modern engines and modern oils can use much longer 
intervals than in the old days.  The days of 3,000 miles oil changes are 
over.  Do a UOA with the TBN test and accept the facts...


Todd
Seattle,WA
'86 GTI, Red of course. (exciting racey car) 273,000 miles
'01 Golf TDI, silver.   (new work car)       290,000 miles
'87 Golf, Polar Silver. (retired work car)   654,000 miles <- Gone to a new 
home :(
http://www.pureluckdesign.com <-Ferrari & VW stuff