Don't blame me for inaccuracies in this list because it's tedious to go through nearly 30 datasheets.
Update thanks to heads up from Quattro Pete. You can access the Germany (German) Castrol datasheets here (link):
These are the Castrol Edge products sold in Germany, Group III or Group IV/V info is what I gathered from the datasheets:
Produktname Code Land Sprache Datum Typ
Fully synthetic (Group IV/V)
(These oils explicitly mention "vollsynthetisches" [fully synthetic] or "synthetisches" [synthetic] but not "HC-synthese" [synthetic hydrocarbon {Group III}] in their datasheets.)
Castrol EDGE 0W-30 463737 Germany German 26 Jan 2012 PI
Castrol EDGE Professional A3 0W-30 467330 Germany German 19 May 2011 PI
Castrol EDGE 0W-40 A3/B4 467465 Germany German 11 Sep 2013 PI
Castrol EDGE 10W-60 463738 Germany German 27 Feb 2012 PI
Castrol EDGE Turbo Diesel 0W-30 463748 Germany German 23 Jun 2006 PI
Castrol EDGE Turbo Diesel 5W-40 463745 Germany German 19 Mar 2012 PI
Synthetic hydrocarbon (SHC = Group III)
(These oils do not explicitly mention "vollsynthetisches" [fully synthetic] or "synthetisches" [synthetic] or they mention "HC-synthese" [synthetic hydrocarbon {Group III}] in their datasheets.)
Castrol EDGE 5W-30 463740 Germany German 19 Apr 2011 PI
Castrol EDGE 5W-30 463740 Germany German 27 Sep 2013 PI
Castrol EDGE 5W-30 465007 Germany German Castrol/Consumer 13 Jul 2006 PI
Castrol EDGE 5W-40 463878 Germany German 31 Jan 2013 PI
Castrol EDGE Formula RS 0W-40 465083 Germany German 04 Aug 2006 PI
Castrol EDGE Longlife II 0W-30 467282 Germany German 19 May 2011 PI
Castrol EDGE Professional A1 5W-20 467327 Germany German 19 May 2011 PI
Castrol EDGE Professional A3 0W-40 467337 Germany German 29 Feb 2012 PI
Castrol EDGE Professional A5 0W-30 467338 Germany German 13 Feb 2013 PI
Castrol EDGE Professional A5 5W-30 467339 Germany German 27 Sep 2013 PI
Castrol EDGE Professional BMW LL04 0W-30 467340 Germany German 19 May 2011 PI
Castrol EDGE Professional C1 5W-30 467357 Germany German 19 May 2011 PI
Castrol EDGE Professional C3 0W-30 467342 Germany German 20 Jan 2012 PI
Castrol EDGE Professional C4 5W-30 467358 Germany German 19 May 2011 PI
Castrol EDGE Professional E 0W-20 468056 Germany German 29 Jul 2013 PI
Castrol EDGE Professional H 0W-20 468210 Germany German 02 Jan 2014 PI
Castrol EDGE Professional H 5W-30 468213 Germany German 05 Jun 2013 PI
Castrol EDGE Professional H C2 0W-30 468230 Germany German 04 Jun 2013 PI
Castrol EDGE Professional LongLife III 5W-30 467369 Germany German 07 Nov 2011 PI
Castrol EDGE Professional OE 5W-30 467370 Germany German 31 Jul 2013 PI
Castrol EDGE Professional TWS 10W-60 467449 Germany German 06 Dec 2011 PI
Castrol EDGE Professional V 0W-20 468317 Germany German 08 Nov 2013 PI
Given the Castrol's infamously inaccurate datasheets, it's hard to make too much out of these. However, it looks like even in Germany the Group IV/V oils are becoming extinct in favor of the far cheaper Group III. So, chances are the "German Castrol" you are getting is a Group III oil. It's probably only Group IV/V if it has a German label and it explicitly says "vollsynthetisches" (fully synthetic) or "synthetisches" (synthetic) but not "HC-synthese" (synthetic-hydrocarbon [SHC] = Group III). However, the ACEA A3/B4 varieties of Castrol 0W-30 still seem to be the safe choice to be Group IV/V.
Update thanks to heads up from Quattro Pete. You can access the Germany (German) Castrol datasheets here (link):
These are the Castrol Edge products sold in Germany, Group III or Group IV/V info is what I gathered from the datasheets:
Produktname Code Land Sprache Datum Typ
Fully synthetic (Group IV/V)
(These oils explicitly mention "vollsynthetisches" [fully synthetic] or "synthetisches" [synthetic] but not "HC-synthese" [synthetic hydrocarbon {Group III}] in their datasheets.)
Castrol EDGE 0W-30 463737 Germany German 26 Jan 2012 PI
Castrol EDGE Professional A3 0W-30 467330 Germany German 19 May 2011 PI
Castrol EDGE 0W-40 A3/B4 467465 Germany German 11 Sep 2013 PI
Castrol EDGE 10W-60 463738 Germany German 27 Feb 2012 PI
Castrol EDGE Turbo Diesel 0W-30 463748 Germany German 23 Jun 2006 PI
Castrol EDGE Turbo Diesel 5W-40 463745 Germany German 19 Mar 2012 PI
Synthetic hydrocarbon (SHC = Group III)
(These oils do not explicitly mention "vollsynthetisches" [fully synthetic] or "synthetisches" [synthetic] or they mention "HC-synthese" [synthetic hydrocarbon {Group III}] in their datasheets.)
Castrol EDGE 5W-30 463740 Germany German 19 Apr 2011 PI
Castrol EDGE 5W-30 463740 Germany German 27 Sep 2013 PI
Castrol EDGE 5W-30 465007 Germany German Castrol/Consumer 13 Jul 2006 PI
Castrol EDGE 5W-40 463878 Germany German 31 Jan 2013 PI
Castrol EDGE Formula RS 0W-40 465083 Germany German 04 Aug 2006 PI
Castrol EDGE Longlife II 0W-30 467282 Germany German 19 May 2011 PI
Castrol EDGE Professional A1 5W-20 467327 Germany German 19 May 2011 PI
Castrol EDGE Professional A3 0W-40 467337 Germany German 29 Feb 2012 PI
Castrol EDGE Professional A5 0W-30 467338 Germany German 13 Feb 2013 PI
Castrol EDGE Professional A5 5W-30 467339 Germany German 27 Sep 2013 PI
Castrol EDGE Professional BMW LL04 0W-30 467340 Germany German 19 May 2011 PI
Castrol EDGE Professional C1 5W-30 467357 Germany German 19 May 2011 PI
Castrol EDGE Professional C3 0W-30 467342 Germany German 20 Jan 2012 PI
Castrol EDGE Professional C4 5W-30 467358 Germany German 19 May 2011 PI
Castrol EDGE Professional E 0W-20 468056 Germany German 29 Jul 2013 PI
Castrol EDGE Professional H 0W-20 468210 Germany German 02 Jan 2014 PI
Castrol EDGE Professional H 5W-30 468213 Germany German 05 Jun 2013 PI
Castrol EDGE Professional H C2 0W-30 468230 Germany German 04 Jun 2013 PI
Castrol EDGE Professional LongLife III 5W-30 467369 Germany German 07 Nov 2011 PI
Castrol EDGE Professional OE 5W-30 467370 Germany German 31 Jul 2013 PI
Castrol EDGE Professional TWS 10W-60 467449 Germany German 06 Dec 2011 PI
Castrol EDGE Professional V 0W-20 468317 Germany German 08 Nov 2013 PI
Given the Castrol's infamously inaccurate datasheets, it's hard to make too much out of these. However, it looks like even in Germany the Group IV/V oils are becoming extinct in favor of the far cheaper Group III. So, chances are the "German Castrol" you are getting is a Group III oil. It's probably only Group IV/V if it has a German label and it explicitly says "vollsynthetisches" (fully synthetic) or "synthetisches" (synthetic) but not "HC-synthese" (synthetic-hydrocarbon [SHC] = Group III). However, the ACEA A3/B4 varieties of Castrol 0W-30 still seem to be the safe choice to be Group IV/V.