Zero offset wider tires for 19" Sport 370Z?
 

Anyone know what size tires you can replace stocks on the 2013 370Z with sports (Rays forged 19" wheels) and maintain the speedo correctly? I think the term I heard when I had a G37S was "zero offset" - idea being you get slightly wider tires but also slightly lower profile such that the overall tire height stays the same and thus the speedo isn't affected.

305/30 is where most people go on the rears and 265/35 on front. Front's are slightly shorter but rears match 100% (where the speedo reads from with the trans and diff)

Use this page:

Tire size calculator

For instance, 275-35-19 and 285-35-19 is 60.6 mph vs 60 mph normally

305-30-19 = 59.2 mph instead of 60 normally, so not really a big deal at all

The tire size calculator will tell about the speedo but how about in terms of fit? What sizes will look best on fully stock Rays size rims? Do any of the sizes discussed rub?

305/30 fits with no problem, lots of room and is as wide as you should go on a 10" sport wheel.

Has anyone determined how much of an issue wider tires presents for throwing rocks onto the fenders?

Not enough to worry about. Just do it!

305 is a HUGE tire, had them on my 997...id be more concerned about extra weight of tire,,,this can all be found at tire rack under specs

Any opinions on whether moving from stock 19" Rays tire sizes will adversely affect handling, turn-in responsiveness/ability or braking?

S-04 305/30 = 33lbs, 285/35 = 32lbs, 285/30 = 30lbs

RE-11 305/30 = 32lbs, 285/35 = 31lbs

Not a huge dif.