Where it says "very little active additive left".

What does that mean? My car runs as well with "very little fuel left" as it does with a full tank.

I think I read that TBN = 2 is as low as you should go. Would be nice if the report indicated acceptable values of TBN. How high is TBN in fresh oil? Does synthetic have a higher TBN or does synthetic make TBN last longer, so to speak?

Also, what was the value of additional filtration in this case? Would the readings have been higher/worse running only the factory filter?

Sixto
93 300SD 3.0

This is Blackstone's explanation of TBN:

http://www.blackstone-labs.com/do_i_need_a_tbn_.html

Generally, HDEO starts out around 12.

The synthetic basestock does not influence TBN, the additives do.


Tim

__________________
2009 VW TDI Jetta Sportwagon 172k miles (rear-ended harder than Elton John on 8/4/13. Total loss)

1991 Volvo 240 142k miles (T-boned by a stop sign runner. Total loss)

Do people get some thrill out of stretching their oil change intervals so they can brag about it? I just don't see the economy of trying to drive over 10K miles on a few quarts of oil when it is by far the cheapest and easiest bit of maintenance you can do to your car. I cringe at the thought of going 20K miles between changes.

I always change mine well before the FSS even comes close to saying to (usually it gives me 12K miles but I change it at 8K). That's less than twice a year for my driving. My oil analyses always come back glowing, everything is low, well below averages and this from a car coming up to 150K miles. OK, maybe it costs me an extra $30-$40 a year because I change it a little early. Compared the other costs associated with driving a MB it is truly not even worth counting! The peace of mind coming from knowing I'm not ruining my engine by squeezing every mile out of the oil is priceless.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Some folks liken frequent oil changes to automotive masturbation.

I think stretching oil changes beyond reason or without data results from a deep-seated guilt complex over having formerly wasted natural resources.

I agree that either extreme is false economy. But I would buy a used car from only one of those folks!


Tim

__________________
2009 VW TDI Jetta Sportwagon 172k miles (rear-ended harder than Elton John on 8/4/13. Total loss)

1991 Volvo 240 142k miles (T-boned by a stop sign runner. Total loss)

For people really interesting in oil change intervals, please go to the original thread at bobistheoilguy.com under oil analysis diesel auto, and READ.

First off, the guy used the wrong oil. Second, the evidence is clear that he has a coolant leak into the oil that ruined the TBN. Third, he probably never changed the bypass filter at all and that's why the wear metals are so high.

If not for those two mistakes, and a coolant leak, he'd be fine. Of course, it is a VW.

240Joe