Need offset help please
 

I'm planning on buying a set of aftermarket wheels for my Z, but I just can't seem to get the hang of this wheel offset thing.

Have a Base with the stock 18" wheels and my understanding is that the stock offset is:
front 18x8 43mm
rear 18x9 15mm

Gonna keep the 18 wheel size but go with TSW Interlagos RF's
front 18x9.5 40mm
rear 18x10.5 27mm

I want to try to get the wheels as flush with the sides of the fenders as possible, but I don't want to have the tires really poking out too much if any at all. So given the numbers above what am I looking at to get the set up I'm looking for to get flush wheels.

Also, I'm planning on going with 245/40/18's up front and 275/40/18's in the back, and eventually will be lowering the car with a mild spring drop (1 to 1.5in) so clearance should not be an issue right? I should also still be able to get the car aligned to factory specs after the wheel mods and even after the drop too from what I've read. But before I pull the trigger on the wheels and tires I just want to make sure everything is going to work.

Thanks in advance to anyone who can help me.

In those widths, look at the offsets of the Nismo rims. They look pretty good as-is, some people get even more aggressive with the spacers.

If you wanted to, you can put a lot more tire width on the rims you want. With proper offset people are running much much more rubber without rubbing (check out the track guys).

Go more aggressive for 18's If you pm me your facebook acct or email address I will add you to the dfw the370z group and you can check out pics and come to a meet to see peoples setups.