what rims dimensions do i need to look for ?
 

I have a 2015 brz with the stock rims on them...17inch ones with tires that say "215/45R17." I will be trying to get enkei rims for the car but do not know specs on what to look for. I know i want 17 inch rims for the car but the offset and other stuff do not know much about it. I will also be getting RCE yellow springs which lower them 20mm front and back. Any help will be greatly appreciate.

If you're interested in getting a set of Enkei's, send me a PM, I've got all the details, can get you pricing, even a full wheel/tire package ready to install on the car when you're ready :)

http://www.ft86club.com/forums/forumdisplay.php?f=24
Look at all the sticky threads.

First of all-- there is plenty of information on the forums regarding fitment and if you look in the section you posted in (wheels | tires | spacers | hub) there are very useful stickies that will answer your questions. You don't even have to search for this info as it is right at the top of the section you posted in.

With that being said:

Take a look @ wheel gallery on the forums for pictures of how each set up will look in terms of fitment: http://www.ft86club.com/forums/showthread.php?t=7535

The tables will show you what size wheel and offset will sit and whether or not it will fit properly under the fenders/will it hit your suspension.

Quick reference for numbers:
Tires: 215/45/17
The 215 references the section width meaning the width of the tire in millimeters.
The 45 references the sidewall aspect ratio, aka sidewall height as a ratio
The 17 references the wheel/tire diameter

More info here: http://www.tirerack.com/tires/tirete...150429213557:s

For wheel sizes
ie: 17x9 +35
Here, the 17 references the wheel diameter
The 9 references how wide the wheel is
The +35 is the offset -- offset is how far the part of the wheel that attaches to the hub sits from the center of the wheel. + offset means distance towards outside of vehicle from center of wheel. - offset is distance going inwards from center of wheel. To visualize, generally a lower offset will make the wheel move outwards and a higher offset will make the wheel move inwards under the fender.

More info here: http://www.discounttiredirect.com/di...gWheelSize.jsp

Finally, make sure you are getting wheels with a 5x100 bolt pattern for our car.