I'll chime in here regarding oil analysis. I had my Toyota 0w-20 analyzed at approx. 30,000 miles on the engine and 5220 miles on the sample. Blackstone came back and said the TBN was 4.7 and try going 7500 miles on next oil change. In addition, the report said Toyota synthetic has some different additives vs. Mobil One-most notably molybdenum, calcium, and magnesium. I'm for sure no chemist or expert in this field, but have always had my oil analyzed every 30k or so, and it seems Blackstone has consistently given me the go ahead to bump the oil change a little longer (usually 2500 miles). I'm sticking with 5k intervals on my 2012 ls460 until my original warranty expires. I pay roughly $6/quart after tax at my local Toyota store-Lexus has in stock as well but charges about $8/quart.

 

Yeah you mentioned that German Castrol a few times and I did a little research on it - I don't think it's available in the us anymore, but everyone swears by it. Castrol has said it is a different formula than their Edge with titanium product (although they of course praise that product).

 

It sounds like Blackstone is conservatively trying to tell you can go much further with that oil, I bet if you were to do 7500, the next test result would suggest for you to go another couple thousand before your next change.

 

Doublebase, I totally agree with you. The same advice was given with my 1990 ls and my 2000 ls reports.

 

Everyone for a time swore by GC because the results from UOA was overwhelming proof. We can debate what goes into the oil but in the end it's the report that counts.
I don't think Castrol was trying to make a superior oil for the public consumption because they never advertised it's superiority. The reason why it was king for a long time is mainly because it has to meet BMW specifications. BMWs as well as many other German makes are friction motors and they get hot compared to Japanese engines. This has everything to do with the kind of driving the car sees and in North America we have a mixed driving culture of both city as well as interstate driving.
A3 specification is important in Europe also because they do extended oil drains.
There is a lot more then meets the eye when considering an oil and just by going by the formulations and tests does not give us a clear picture but a good UOA does.

 

I sat next to a BMW shop foreman at a dinner a couple of months ago and he said BMW has an oil change schedule of 15k miles (at least that's what I think he said). I scoffed at that, but he said he does it himself in his own BMW and has had no problems. I didn't think to ask him what oil he used - I know it was Castrol - but I don't know if it was the German Castrol. Still I was surprised to hear this, especially from a guy I know has fixed cars for a long time.