I am trying to find out the offset of the stock 18" wheels (18/8 and 18/8.5) on the Z. I have the stock tires on now (225/45/18 and 245/45/18) on the stock wheels. I just got new wheels (18/8.5 +35 and 18/9.5 +35) the tires I want to order are 255/40/18 and 275/40/18. I am trying to figure out what spacers I will need with the new wheels and tires if any. I am thinking 10mm or 15mm spacers but I want to make sure nothing will rub, my Z is not lowered at all. I think that the stock offset is +30 but I am not sure. Thanks

 

Pretty sure stock offset is +33. I would go with atleast 20mm all around if not 25mm.

 

O.K., I an still new to all this so please dont flame me, but...... I am trying to understand all the numbers. So going from a 225 to a 255 on the front that means that the new tires will be 30mm wider then the stock 225 is this right so far? This means that the new tire will be 15mm wider on each side of the tire, right? So if I understand this correct (and I am sure I dont) that means that the new front tire on the new front wheel will stick out on the side of the car 13mm more then the stock tire is now? And if I use a 15mm spacer then it will stick out 28mm more?? Please let me know if I am getting this right or not. Thanks much

 

OEM 06s are +30F +33R

With the 8.5+35 you're going to want ATLEAST a 15mm spacer.
9.5+35 You're probably going to want Atleast 15mm spacer.

With the15mm spacers, you're going to look like this:


http://www.1010tires.com/WheelOffsetCalculator.asp

 

see page 9-9 in your manual for factory offsets (at least for the '04 manual). Istan's OEM ## for '06 are also correct for '04 with the sizes you describe (see link): http://www.courtesyparts.com/betasit...issan-350Z.pdf

 

Yeah, the 03-05 OEM is +30F and R

I looked through his previous posts and he had mentioned 06, so I assumed 06

 

Yup, Its a 06 (sorry)