I think you will find that 240z is of the lug centric design ie the wheel is supported by the studs
A standard steel wheel has a gap of a few mm round the hub
Nick
Don't a lot of people run lug centric wheels? (wheel hole doesn't fit tight around hub)
I'm pretty sure majority of people run lug centric, id say hubcentric would be less common as its difficult to have after market wheels fit your hubs perfectly. Or I could be wrong...