This might be of some interest ... I had engine oil and ATF samples analyzed on my not nearly new xB (almost 50K miles, bought new in July 2003). I've been running mostly on dino oil at 5K intervals and driving mostly freeway miles. Only engine mod of consequence is the Injen short ram (IS2100) installed at about 15K miles, no air filter change yet.

After 4500 miles on Pennzoil 5W30 with Toyota filter:

TBN: 2.20 (just about time to change)

Iron: 3 ppm
Chromium: 0
Lead: 0
Copper: 3
Tin: 0
Aluminum: 1
Nickel: 0
Silver: 0
Silicon: 19
Boron: 18
Sodium: 0
Magnesium: 10
Calcium: 1706
Barium: 0
Phosphorus: 766
Zinc: 980
Molybdenum: 297
Titanium: 0
Vanadium: 0
Potassium: 0

Fuel: < 1%
Viscosity: 9.07 cSt @ 100C
Water: 0%
Glycol: No

Having used an oiled gauze air filter for some time, I expected to see elevated silicon levels from ingested dirt. I'm happy to see that the silicon reading is only 19 ppm, most of which could be explained by defoaming additives and the oil pan seals.

Viscosity is just a bit light for 5W30, at 9.07. That's within spec for a 20-weight oil ... I guess I was running on 5W-20 after all Otherwise everything seems OK.

What did I get for my $25 and burned fingers? A bit of peace of mind and some hard data. It seems to me that the "severe service" 5000 mile oil change interval is just about right for the average driver and dino oil. I wonder if it's enough for true "severe service" though.

 

Interesting data there but I like to change my oil every 3K miles...

 

Who does this type of analysis??

 

Oh yeah, forgot the ATF analysis ...

Fluid is Toyota T-IV with 19K miles (changed at 30K ... hey, it's cheaper than a new transmission).

Iron: 49 ppm
Chromium: 0
Lead: 10
Copper: 12
Tin: 1
Aluminum: 23
Nickel: 0
Silver: 0
Silicon: 15
Boron: 40
Sodium: 0
Magnesium: 1
Calcium: 72
Barium: 0
Phosphorus: 223
Zinc: 14
Molybdenum: 0
Titanium: 0
Vanadium: 0
Potassium: 0

Viscosity: 5.48 cSt @ 100C
Water: 0%
Solids: Trace
TAN: 1.39

Recommendation: No action required.

Viscosity is down to 5.48 at 19K miles. I can't find any official numbers for Toyota T-IV ATF but Mobil 3309 ATF (brewed to Aisin-Warner specs) is supposed to be 7.2 out of the bottle. I'm sure it's fine for now but I'm sticking to a 30K service interval no matter what Toyota says.

 

I had it done by Oil Analyzers Inc. (kits and equipment available through Amsoil). OAI and Blackstone Labs are probably the two best-known labs that cater to the individual consumer.

Oh no, now I've done it ... I mentioned Amsoil ... prepare for major topic drift

 

I noticed the Calcium level is pretty high. Are you giving your xBaby milk?

 

calcium builds strong bones! XD

 

If I could breast-feed my xB, I would.

Seriously though, calcium compounds are used as detergent and wear additives. Many engine oils contain 2000+ ppm.