Here are some product references from the tires brand "Continental" associated with their corresponding EAN-13 code:
REFERENCE_CONTINENTAL EAN-13
127400 4019238104899
127600 4019238104929
127800 4019238104936
128400 4019238104967
128800 4019238104981
129000 4019238105001
130000 4019238105094
130400 4019238105117
132700 4019238105209
133100 4019238105223
134500 4019238105247
136300 4019238105308
200020 4019238448832
200021 4019238453751
200034 4019238491746
200114 4019238798784
200115 4019238798777
200116 4019238798760
200117 4019238798753
200118 4019238798746
240137 4019238267365
240138 4019238267372
240141 4019238312119
240142 4019238267389
240144 4019238312126
240151 4019238364170
240246 4019238109061
240372 4019238281712
based on http://gepir.gs1.org/index.php/search-by-gtin, I understand 4019238 is the prefix of Continental, then comes 5 digits and then comes the validation digit. Assuming that a manufacturer creates new EAN's based on their own product references, is it possible to guess the complete EAN (or GTIN) for other references from Continental? For example:
REFERENCE_CONTINENTAL EAN-13
282038 ?
282040 ?
282044 ?
Thank you very much for any help
No, that is not possible. The product part of the EAN (GTIN) code is arbitrarily chosen by manufacturor and there is no need to correspond to a product number in any way. You simply cannot guess the EAN from a product number.