Hi all, I have the 18 factory rims...All four Rims are 18x8...Front tires 225/45R18 91W... Rear tires 245/45R18 96W....Question is? How large can I go without any modification? Thanks for all the assistance....Dave

 

Well, if all 4 are 18"x8" then you just have front rims (unless somethings changed I don't know about). The rears are 18"x8.5".

Anyway, IMO I wouldn't go any wider than 245's front (8x8) and 265 or 275 rear (8x8.5).

I think some have gone wider (I think) but it just doesn't look good to me.

 

That's what I thought but the owner's manual, page9-9, states Roadster 18s front and rear are 18x8 inches Coupe rears are 18x 8.5......Need to find out acurate answer? Thanks for the help on the width sizing....Dave p.s. Just checked nissanusa.com and the Roadster does have 18x8 all four.....Can I go 255 rear and 245 front?

 

Only the Rays are 8 and 8.5 the other 18's are 8 all around.

You should be able to go with 245/40 and 255/40

 

My stock Tourings were 8x8 f & 8x8.5 r. Are you just refering to the roadster?

 

Unless you have an '05...the 18s are an option even on the touring......And yes, only the roadster has 18x8 all the way around.....18s were a $1200. option in 2004 on the touring....

 

Thanks a bunch Gus...I was debating whether or not to call you and ask.......Dave

 

Feel free, even better come to the Sunday cruiZe

Here are the wheel specs from their respective manuals, I don't have the 05 manuals so not sure how wheels cheaged other than the Anniversary ones. The only see thing I see different is on the roadster having the 17 X 7.5 and 17 X 8 and the 18 X 8 all around and no 8.5 rim.

 

You'll want 245/40 in front and 245/45 or 255/45/ in back to maintain the stagger. These are the biggest sizes you can go with the stock 18s, that are in fact 18X8 all the way around. Only the Track Rays are 8.5" in back. 255/40s will be too low.

Lou

 

Actually a 245/40 and 255/45 combination would increase the stagger too much. Stock 17' stagger is +0.39, stock 18" stagger is +0.71, the combination of 245/40 and 255/45 will result in a stagger of +1.32 while the combination of 245/40 and 255/40 will result in a stagger of +0.31 and 245/45 and 245/45 will result in a stagger of +0.35

 

I'm pretty sure I going with The Toyo Proxes T1-S 255/45ZR18 99W in the rear, and 245/45ZR18 96W up front.....I'll know monday if they have them local......I found them for $188. a tire plus tax.........and mount and balance..etc....Dave

 

westpak

Not to start an argument here, but:

Using the Michelin Pilot Sport Spec. Sheet

OD with 225/45 is 25.8"
OD with 245/40 is 25.8"

OD with 245/45 is 26.8"
OD with 255/45 is 26.9"

So - The stock stagger is .5" (1/2 of 1")
with 255/45 it's (.6" (1/2 of 1.2")

Not enough to notice, and you will notice the width increase front and rear.

BTW the OD with a 255/40 is 25.9" - So you would essentially lose the stagger, and as I said the tire would be too small in OD, and look funny in the rear wheel well.

Lou

 

No argument here, just education. I didn't use the specs above to come up with my numbers but rather formulas so I could easily plug in different sizes to see how I stood with the stagger.

If you use the formula which should be multiplying the tread width (245) by the profile (45) to get the sidewall height then converting to inches and multiplying by 2 followed by adding the wheel diameter I get 26.68 which is close to the specs mentioned above but when I do the formula for the 255/45 I get 27.04 which is a big difference, about 1 inch. Which is right? I would think my formulas would be, but who knows maybe there is another factor in the manufacture of the tire I am not aware of, any ideas?

But I just did the 255/40 and get a diameter of 26.03 which is close to yours. Hmmmmmm

 

I'd like to go 245/45 f & 265/45 r on my Track Ray's. Is that doable? If so, what do I need to change (if anything) regarding offsets, etc. and what impact will it have on VDC?

Thanks!

 

Well according to my spreadsheet you would have the same identical stagger as the stock Rays setup, you would be increasing the diamters of the front and rears by the same amount, just under 3/4" in diameter. And unless you are lowered and with spacers you should be ok with the fender.

If you go with Toyo T1S' I have two 245/45/18 in my garage, one barely used and the other with about 10K miles but no feathering and hardly any wear.

The tire on the right of the first pic and second pic is used about 12K miles and still has good tread left as you can see.

The tire on the left of the first pic and in the last pic is almost new with only a couple of hundred miles on it.

 

Well as the story goes, I ended up going with Michelin Pilot Sport AS 255/45/18 rear and 235/40/18 up front...Very pleased...Gus was on the mark once again....Dave