mario60185

ok so i just got ssr professors in 18x9 and 18x10.5 30off. front and rear.
So my problem is tire size. PLEASE someone help me.
to start my main problem is what sidewall height to get. 35 maybe too small for the crap streets of chicago....so i was thinking 40 series sidewalls.....then i came up on a problem..whay the hell do some 40s look like 50s and some 45s look like 35s?
for ex. my girl has a scion tc with 205/45/17s , now her 45s look like some 40s or even 35s...

My thought is that cause i know the sidewall measurement isnot just the sidewall height in mm, it has to do with the overall tire dimensions, maybe if i "stretch" the tires with a 40series it wont look like a big *** sidewall.
Let me explain: recomended for my widths is 255 and 275 so if i get a 40 series in 245 and 265 will the sidewall look smaller than 255 275/40. did i explain that right? heres some pics...damn couldnt findem...but this guy has 35 series that look like 40s. hes got 245 and 285 on the same width as me 9 and 10.5...what the hell ?
please help me!

Chad68

iTrader: (1)

I would love to help you but your question/questions are worded way too confusing.

One of the reasons some 45's look like 40's and blah blah blah is because it depends on the width of the tire, not only the profile number ie 30,35,40 etc.. The 30, 35, 40 etc is the profile (sidewall height) in relation the tire width.

Example, a 295/30's sidewall might look a lot like a 245/40 because the sidewall height is 40 percent of the 245's tire width, contact patch width or bead to bead meausrement, not sure wich. Or some sheet like that LOL.

Notice how some of the Riced out Hondas have tires that are soooo low profile that they look like they used rubberbands as tires? That's cuz they run tires something like 215/30/19 or whatever. Now if it was a 295/30/19 tire, the sidewal would be a lot taller.

Now you confused me, errrrrrrrrrrrr.

mario60185

yeah man!...seriously though thats exactly what i was thinking ! sooo if i get 40 series tiers in order to feep them looking smaller(sidewall) i should keep the width down to a minumum? so for ex.....a 245/40 would have a bigger sidewall than a 235/40?

Chad68

iTrader: (1)

Another way to look at it is like this.

When I buy my 350z in about 12 months, I am getting silver Axis Hiro's.

I am going to be using 19x8.5's wheels in the front and 19x10.5's in the rear.

Rear tires will most likely be 295/30/19's and the fronts will be 255/35/19's.

The overall diameters and sidewalls will be and look the same but the rear tire is significantly wider than the front.

I will have to look at the tire manufactures spec chart again but I think the fronts were about .3 of an inch smaller diameter than the rear but well within limits, which is cool cuz I would actually prefer the front overall diameter to be a tiny bit (<.5") smaller than the rears anyway. The last thing you want is to have the front sidewalls and or diameter being larger, even by just a little than the rears, whick looks like crap and I'm sure doesn't do a (good) thing for handeling anyway.

Ok I'm done, off to try to find more pics of the Veilside verson 3 rear wing I'm getting :-D

mario60185

thanks bro....what tire size do you suggest for me? 9" wide front and 10.5 rear? i was thinking 245/40 and 275/40?

i want the 40s for now mostly cause there alot cheaper.thanks for the help

mystik_350z

if you are running a staggered setup, you wanna try and have the rear sidewall smaller. for example, if the front tires are 245/40, you wanna try and have the rears 275/35 that way the rear don't look ginormous compared to your front tires.

as far as recommendation of what size tires, there is a whole thread on it somewhere in this forum.

mario60185

why would the rear sidewall be smaller? wouldnt it look funny? if anything shouldnt the rear be a tad bit taller?

Z BOY

iTrader: (41)

mario, you may find the answers to your questions in this thread:https://my350z.com/forum/wheels-and-tires/73898-correct-tire-sizing-when-changing-wheels.html

mystik_350z

i am mistaken, i apologize. i should have read that before i chimed in. ::insert foot into mouth::

because of the 350z characteristics, it is necessary for you to follow the above mentioned thread. i was just going by other models that do not have vdc, abs, etc. like the toyota MR2 and supra (can you tell im a toyota guy?).

and to answer your question if it will look funny, it won't. if you have a tire that is 245/40, the 40 is the percentage of the 245. now you have the rear tires which are 275/40, and 40 percent of 275 is more than 245. so to make the tires look even, most people try and get smaller profile tires in the rear.

i hope that clarifies things.

Chad68

iTrader: (1)

Hey dude,

I was looking at a tire chart and if you got crap roads and you're running 18x9's in the front and 18x10.5's in the rear, I would go with 295/35's in the rear and 255/40's in the front. The overall diameter on the rear would be 26.1" and the front tires are 25.9". sweet!!

The Tirerack website is extremly helpful. Hope this link comes thru for ya.


http://www.tirerack.com/tires/Spec.j...omCompare1=yes

Chad68

iTrader: (1)

Just be glad you don't have a C-5 Corvette. The ones I have seen (stock) have 17" front wheels and 18" rears. They actually have taller sidewalls on the front than the rear and it looks ohhhh so NOT right. I hear they run rims on the Vette that way due to understear or something.

Z BOY

iTrader: (41)

sorry, i beg to differ...smaller sidewall in back looks horrible, imo.

mystik_350z

that's your preference. i like my tires to be even.

i don't think you're understanding the concept in it's entirety. the only reason the tire in the rear has a smaller profile is to match the sidewall of the front tires. hence, the tires looking even. if you were to get the same profile as the front in the rear, the rear tires would be fatter than the front, if you like it that way, that's fine. but i think most people like to have their wheels and tires evenly matched.

1nate7

iTrader: (19)

Actually, almost everyone runs the same profile front and rear with staggered widths because thats the way Nissan engineered the car. The stock 18" tire sizes are 225/45 and 245/45, same profile with wider tires in the rear giving the rear an overall diameter 1" bigger than the front. In your case I would run either 245/40 front-275/40 rear, or if you want a bit more sidewall and width you could run 255/40 front-285/40 rear.

mystik_350z

i understand and we did go over that. i was talking about most any other rwd cars, i was talking in more of a generality.