Originally Posted by swamp2
They do not "choose" a wheel they design their own, perhaps what you meant, just making sure. Just like the rest of the car wheels are a compromise. They need to be a balance of strong and light weight. They certainly need to be able to handle some small curbs and large pot holes. Super lightweight racing wheels and those that weigh the same as racing wheels can not stand the abuse that the OEM BMW wheels will stand. Eveything is a balance, BMW just made the (good, IMO) decision to err a bit on the conservative side.
I was of the impression forged = very very strong