I was recently new, so I will lend a hand, friend.
4.8 is the quoted e92 time, which is conservative.
BMW quoted the e46 at 5.2 for reference.(even tho drivers achieved 4.8)
Therefore, we can expect the e92 will do much better than 4.8...
e46: 5.2 >>> 4.8
e92: 4.8 >>> ???