stock rear tire on sport package is a 275 on 10" wide, and it's definitely not stretched. 285 or 295 would be good on a 10.5, but I think 295 is more of an odd size so the 285 will be cheaper.

If you aren't doing these for performance reasons, is there any real reason you want 12" wide in the back? is it for the style of having huge rear tires? If there isn't a big reason for it I'd stick with 10 or 10.5 up front and 11 or 11.5 out back. you could do 275 or 285 on the 10, and 305 on the 11. If you are set on the 12 then by all means get the 12 and run 325 in the back. I'd also suggest looking into tires for that size and making sure the tires you want come that wide.

im not set on 12 , i just like the style of having a wide tire , not totally sure what im gonna go with yet , if i can find decent tires for a decent price ill get the 12 , but if tires are an outrageous amount of money ill just get the smaller 11 inch rim and do 9.5 in the front

IMHO - from the sound of things you are better off sticking with a 10.5-11 rim with a higher quality tire rather than going 12 for no reason with a crappy tire. Its really not going to visually look any different as long as you get the correct offset.

1. Set a budget
2. Buy the best in that budget.

You'll kick yourself for going with a crazy 12 inch rim and purchasing some cheap tires that cause performance issues that down the road may lead to unhappyness or worse, and accident.

Good call, honestly the tire cost is going to be the cost that ends up emptyin your wallet over time. You could buy $4,000 wheels and put $1,500 worth of tires on (expect at least that with 20's that wide), but you gotta figure every 20k miles you are going to do it again, at 60k you have spent more on tires than on wheels. Not to mention 20k on sports car tires is pretty damn good depending on how you drive :driving:

Well said. I was going to originally go with wider wheels on my setup, but then when I was looking at tires I figured I'd rather spend a little extra and get quality tires each time I need them, then go wider and end up with junk tires. I went with general exclaim UHP's on my last car, and while they are great for the money, they had way too much sidewall flex to get good responsiveness out of a Z.

great advice caravanshaka , i looked for 12 inch by 20 inch tires and there about 400 bux each , i dont really wanna b spending all that money once a yr... im thinking 11 in the rear and 9.5 or 10 in the front , i guess i gotta look for either 265 tires (9.5) or 275 for the 10 inch

so if i go with 20x9.5 i need a 265/30 or 35/20 tire

20x11 305/25 or 30/20 tire ??

i looked for tires those sizes and theres not many to pick from ;(

is your car a base or sport? going to compare new tire sizes to your current ones and figure up the best for you. any idea what tires you want?

i have the the navi and touring package no sport , any tires will do , as long as ill get at least a yr outta them and there not 400 bux each (id like them around 200) , they dont have to be the best just decent

ok, on the 9.5 front go with 255/35/20 (27" diameter)
on 11 inch rear (or 10.5 if you can) go with 295/30/20 (27" diameter)

these are the optimum sizes to stay close to stock diameter. you might be able to go with 265/35 and 305/30, but your diameter is going to be 2% off of stock, which may cause issues with TCS, I'm not sure what the threshold is with the 370 yet.\

awesome thanx caravanshaka , with those sizes the tires wont look stretched or anything ? im also concered about the safety of a stretched tire

what about sport plus everything else?

http://www.the370z.com/wheels-tires/...s-tcs-abs.html

This is a good reference point for stock tire sizes and the TCS.

You can then use the following tool to compare the new tires you are looking at to the stock tires and check the variance in diameter. you want to keep them as close as possible, and I believe 1% variance was the threshold on the 350z for the TCS started acting funny.

Tire size calculator

nah, you are going 10mm wider than the stock tire on the sport package up front, and it's 1/2 inch wider wheel which is about 13 mm if I recall. It will basically look like stock.
For the rear you are going 20 mm wider tire with a 25 mm wider wheel than stock, again it will basically look like the stock sport package setup. You can go with a 10.5 inch in the back and the tire will fill it out a little better, but that is a personal preference. I'd do the 10.5 just to be consistent front to back with only a 1 inch variance in wheel widths, just like stock variance from front to back.

awesome thanx caravan

i hate to burst some bubbles here, but id love to see 19/20" tires that make it to 20k miles.... especially if you guys drive even moderatly aggresive from time to time. you compound this with lowering and not getting the correct toe/camber/ect.....