I was wanting to put a 305 on the back of my Z. I was wondering what the offset should be on a 19" rim? Also can someone explain how you measure offset and how they come up with the right measurement for the look you want?

 

https://my350z.com/forum/showthread.php?t=141766

 

https://my350z.com/forum/wheels-and-tires/175576-how-to-read-a-rim-chart.html

Noodle had a quick an easy explaination. Hope this helps.