We threw one of my front 15x7 Rota Slipstream wheels with 205 RA-1s on the scale versus the same size wheel in a Volk CE28 with Hoosiers and the Volks+Hoosiers were 5lbs lighter. That's a lot. IIRC the Rota's were 30 (31lbs?) with the RA-1 and the Volk was 25. And just for reference the Volk front wheel in 15x7 is 9lbs...