So Tinman, you've got a Cleveland in your 330i right?

Cuz we all know this is the Cleveland Forum right? BTW, most oils now have very good antoxidants and can easily go 3,000 miles between changes and "full" synthetics can usually go double that with a new filter and 1 more quart @ 3,000 miles. Parafin is the culprit (viscosity improver) that causes sludge accumulation. More oil manufacturers are reducing the amout of parafin in current oils to "reduce sludge". Mobil 1 has lost a lot of the zinc it used to have and even though it's synthetic , can be tough on flat tappet cams. When in doubt use a zinc additive to boost the oil the government has forced oil companies to manufacture.
One more night at the Holiday Inn Epress for me!
Randy