135i/335i. The standard engines 340 bhp will be replaced with 455 bhp. Z4 Main article: BMW Z4 A 2-seater roadster and coupé which succeeded the Z3 . From 2006 the Z4 Roadster is available as a 3.0i (3.0 L I6 with 215 hp), a 3.0si available with the new generation 3.0