This car is based on the BMW Z3 and the BMW M Coupe. European M Roadsters built 1998 to 2001 had the same engine (S50) that powered the 1995 to 1998 M3 Evo with 321 bhp and 350 Nm (258 ft.lb). North American M roadsters built 1998 to 2001 had S52 engine ( based on the regular M52 engine ) with 240 hp and 320 Nm (236 ft.lb). The 2001 M Roadster appeared worldwide with the new 3.2 L S54 engine. This was the highest specific output naturally aspirated production engine ever made by BMW (not counting S70/2 GTR LM engine from the McLaren F1 LM) when it was applied in the M3, in M Roadster form it produced 325 bhp (320 hp) and 353 Nm (261 lbf.ft) of torque.
BMW will introduce an M version of the Z4 in 2006. It will use the same 3.2 L engine as the outgoing car.