I just did some more research. It looks like 1156 actually has a different spec than 7506.
1156 bulbs are 12.8v / 27W while 7506 is 12v / 21W.
If you have a euro carrier, chances are the bulbs used are 7506/7507. I've done so much research on this the past half hour that I now have not a single clue what type of bulbs our carriers are actually supposed to use, as in 7506 or 1156? Or, 7507 or 1157? It's really damn confusing.
I'd be inclined to think that we'd use the 7506/7507 bulbs instead. I'm going based on logic; why would the european ones be different than the US ones? They're essentially the same bulb carriers from what I understand...