Whats a good conventional oil for my 06 M45? The car has 34,790 miles and the engine was replaced at 34,055. So its still breaking in. What would be a good oil for mostly city driving. The car barely sees the highway and is driven maybe 5 miles a day on some days. Right now I have Castrol GTX in it and would be to try Mobil clean 5000. Any suggestions?