Originally Posted by ChrisD46
The more I read and research - the more I come back to the defacto standard of the synthetic oil 5K mile OCI with a good oil filter as being about best if you want to keep a vehicle running past 250K miles .
*First , TBN is not the be all - end all in determining how long you should go with an OCI .
*Next , by 5K miles of mixed driving (majority of what we all do) the oil is getting dirty , more abrasive with deposits , fuel dilution starts climbing , etc. so the oil should be replaced .
*Vehicle manufacturers are in business to sell new vehicles - the 7.5K to 10K mile OCI recommendations are only listed in the OM to get you to 100K miles (in most cases) .
*Castrol EDGE EP and M1 EP stating they can do a 20K OCI is marketing (and dangerous marketing at that) only possibly realistic if you do 100% high way travel ; At most I would run a 6K - 7K mile OCI .
*More vehicles today (and growing) are GDI / Turbo engines where by the 5K Mile OCI protects against fuel dilution and soot (abrasive) to keep levels down to an acceptable level .
*European BMW , Mercedes , etc. OCI's of 10K or more just can't be good for ultimate engine up keep long term unless driven on the German Autobahn full time .
*With previous synthetic oil 6K + OCI's with Sea Foam added last 150 miles - oil would get noticeably darker ; at synthetic oil 5K mile OCI's Sea Foam added last 150 miles showed little oil darkening .
* With a synthetic oil 5K OCI I notice less metal shavings in my plastic oil drain catcher afterwards versus 6K + OCI's .
*Disclaimer* : Your mileage can and will vary from what I have listed - however in modern engines using an approx. 5 qrt. sump I believe the 5K OCI is about the best recipe with a synthetic oil for keeping an engine running well past 250K miles ...
Oh ya, well you should have a look at a sample just taken from someone who ran 15000 miles on a interval and when sampled Blackstone even recommended 20k. Amsoil ss series. All highway of course. But hey it's your money, you can waste it anyway you like.
It all depends on your oil and how you drive, and vehicle as well. But don't tell me every vehicle needs a 5 k oil interval. It all depends on your situation and car.