Here is UOA from my BMW after 4,600 miles. I changed it bcs. regular track season was coming.
This oil didn’t see track, but saw a lot of hard driving. Dropping kids to daycare every morning, 20 mile round trip. Picking them up, once a week skiing and pushing car as hard as possible in the mountains.
This is first oil that was put in after I installed oil cooler from 335. Cooler is brand new as well as thermostat. Oil filter housing and oil cooler lines are used. UOA looks IMO really good. Minimum shearing. But TAN is bit high. I have never seen TAN like this on Castrol 0W30 or 0W40.
This is oil cooler I installed:
This oil didn’t see track, but saw a lot of hard driving. Dropping kids to daycare every morning, 20 mile round trip. Picking them up, once a week skiing and pushing car as hard as possible in the mountains.
This is first oil that was put in after I installed oil cooler from 335. Cooler is brand new as well as thermostat. Oil filter housing and oil cooler lines are used. UOA looks IMO really good. Minimum shearing. But TAN is bit high. I have never seen TAN like this on Castrol 0W30 or 0W40.
This is oil cooler I installed: