I've actually owned 2 sets of these rims and one set of genuine wats, I investigated how they were related and found out that black racing commissioned watanabes or there manufacturer to make these wheels for them, the difference is actually in the offsets, the reason black racing built there own wheels was Wantanabe didn't supply the offsets they wanted, as for weights I was under the impression that they would be the same...... Until I weighed them myself ( comparing apples with apples) and the BR's came in lighter than the wats by a very small margin .