I would be inclined to call BS on this BUT there could be a difference. Car&Driver has an article about how to read the sidewall of a tire and this is pulled from that link:
"12.) ORIGINAL EQUIPMENT (OE) MARKING: These letters—or a symbol—indicate that this is the automaker-specified version of a tire that came as a car’s original equipment. These tires can often be a very different blend of rubber compound compared with the off-the-shelf variety of the same tire, even though the tread pattern is identical. Examples of OE markings: General Motors—all have a TPC SPEC number; BMW—most have a five-pointed-star symbol; Mercedes—some are emblazoned with “M0”; Porsche—all have the letter “N” followed by a number, i.e., N1, N2, etc."
Again I don't think there is a difference in this case but I don't know for sure. We need someone like Lemans to jump in here and clear this up.
Current: 2015 F80 M3 (SS, Full Black Interior, 6MT, LED Lights, Adaptive Suspension, 19's)-Mods:KW Clubsport Coilovers, M Perf Exhaust
Previous: 2013 E92 M3, 2013 F10 M5, 2009 E90 M3, 1998 E36 M3