if you're basing it on the "TwinPower" label, thats the marketing term bmw has adopted for both the N54 and the N55.
does your sticker say Valvetronic on it? no valvetronic, its not the N55.
(the N55 has not been epa cleared yet, so there's 0 chance they're releasing cars with it, there would be huge fines for BMW)
Past: 2001 Orientblue E46 330i
Past: 2004 S60R 6MT
Past: 2007 E90 335i 6MT
Past: 2010 335xi ZMP, BMW Performance Kit, BMW Performance Exhaust
Present: 2013 335i 6MT ZMM/ZDH/ZTP/3AG/494/508