Numbers just don't add up

I have a VX Commodore with a Supercharged V6. I have been looking at performance specs on both the RACV and the Holden websites, and both show the Supercharged V6 and the Standard V6 as having similar 0-100km/h times. The RACV even shows the Standard V6 having 0-100km/h at 8.5 secs and the Supercharged V6 at 8.7 secs. I don't know how the times can be identical when the Supercharged V6 has greater power (171kW to 152kW) and greater torque (375Nm to 305Nm). I know other factors come into consideration, such as car weight, but I would like to know why I paid extra for a supercharged engine.