I've been using GC "German" Castrol Syntec 0W-30 European Formula for years. After I recently bought some more, I noticed that the new bottles no longer list it as being VW 503 01 rated. The old bottles said that it exceeds VW 502 00, 505 00, 503 01. The new bottles only say that it exceeds VW 502 00, 505 00. It is my understanding that VW 503 01 is a more stringent standard for long life oil with higher HTHS for turbocharged gasoline engines. I checked the Castrol USA website (http://www.castrol.com/castrol/datasheetsearch.do) and their product data sheets (http://www.castrol.com/liveassets/bp_internet/castrol/castrol_usa/STAGING/local_assets/downloads/p,q/pds_syntec_usa.pdf and http://www.castrol.com/liveassets/bp_internet/castrol/castrol_usa/STAGING/local_assets/downloads/p,q/Edge_BLACK_PDS_Sept_2011.pdf) no longer list VW 503 01. An old data sheet found elsewhere did list VW 503 01. Can anyone help me understand why Castrol no longer lists VW 503 01? Can anyone recommend another oil that still meets VW 503 01 and ideally MB 229.5 which is moderately priced and easy to find (retail) in the USA? Should I be looking for a VW 504 00 approved oil to replace 503 01?