A while back I wrote here that I was letting my oil change go for 10,000 miles. I cut open the filter and sent a sample to an oil analysis laboratory. Now for the results!

The filter is holding up fine and while contaminants can be seen on the filter medium, there is still some life left in the filter.

There are almost no wear metals in the oil sample. Protective additives are still strong. The TBN is around 3 (new oil is about 10, you don't want to reach 1) and this may be because I am adding fresh oil on a regular basis as the rear main seal is leaking.

The lab report suggests that the metals content of my oil sample were mostly close to oil with 5500 miles of use. Win! My oil fill is Shell Rotella T5 10W30. It's $14/gallon at walmart. I'm pretty thrilled.

So, I decided to keep letting the SERVICE light tell me when to change oil, and will change the filter every time.

See the filter pictures and lab report at the imgur gallery: Mann W917 10,110 miles - Album on Imgur

Here's an analysis on a sample of virgin oil: http://www.pqiamerica.com/June%20201...llatT51030.htm

 

Good information. Thanks for sharing!

With a dripping mainseal, how much makeup oil did you need to add? If your pass-through rate is high enough, things would definitely work out well for an extended changeout plan...

Also, have you considered the Fram XG? Not your typical "orange can menace" by the numbers, and IIRC it uses a better filter paper than the Mann:

Oil Filter Comparison Study - GM Truck Central

Oil Filter Media Comparison Images - GM Truck Central

Cheap enough @ Wally if one gets the XG16, which should fit the B6304 without issue:

PH7328

XG16

I just tried on a TG16 after seeing the comparison to the Wix/NAPA I'd been using. Better value; but I'll be moving along @ next changeout to something higher up the food chain...

Just a couple of ideas

 

Key is how much oil is being added due to the leaks? If you have a leak big enough you may never need to change the oil!
I think 10k is pushing it; I use full syn (any brand 10-30) and change every 6-7k with a MANN filter--never a problem after some 30 years.

Besides, Volvos engines, especially Red Blocks, are pretty much the last thing to fail so I worry more about the transmission, overheating, cooling system, leather, headliners, etc.

If I had a White Block I'd worry much more about the T belts and assorted than the oil!

 

I put about 2 1/3 quarts in between oil changes. I think this propped up the TBN a little. This oil started out at about 10, you don't want to reach 1 and mine was at 3.