Whats up everyone? I have a question. I have a 2004 G35 sedan with stock 17's on it. Im upgrading my wheels to the 2008 G35 sedan wheels. The new wheels are 18x7.5 (front) 18x8.5(rear) staggard. It says that the stock sizes for that are 225/50/18 front and 245/45/18 rear. Well with that said the Kumho Ecsta SPT's i want to run they dont carry both sizes. They do have the 225/45/18 for the front and the 245/40/18 for the rear. How much difference in fender gap would it be if i ran the original size compared to the Kumhos i want? Is there a big difference between seeing a 50 series compared to a 45 series on a car? Any bit of info will help. Thanks!

I'd like to dispell the idea of sidewall "series" because it makes absolutely no sense when we're talking about fender gap.

The "series" (which isn't the wrong term, just a very vague one) refers to the aspect ratio of the tire. Meaning it's the sidewall height as a percentage of the width of the tire.

If you go 5% smaller in the front and rear, you'll be losing approximately 1/2" on both the front and rear which equates to almost 1" in total diameter.

Your speedometer will also be off by a ratio of 1:20MPH.

See my sig if you're interested, PM me. I can sell two instead of all 4.

Thanks for that info, but will the difference in those tire sidewall aspect sizes make a noticeable difference? I want to run the Kumho SPT's because they are a good cheap tire, im just wondering if a 45 ratio in the front and a 40 ratio in the back will look funny, and no i dont plan on lowering it. LOL

Sentientbydesign wrote:
PM me.

Expain to me how this works... Am I missing something?

dolamite wrote:Thanks for that info, but will the difference in those tire sidewall aspect sizes make a noticeable difference? I want to run the Kumho SPT's because they are a good cheap tire, im just wondering if a 45 ratio in the front and a 40 ratio in the back will look funny, and no i dont plan on lowering it. LOL

http://www.miata.net/garage/tirecalc.html

Try using that. It should make visual sense.

I personally wouldn't do it. I think the gap is big enough.

I originally was going to go with those tires, but I decided to get some used ones instead.

Beanor wrote:
Expain to me how this works... Am I missing something?

Tengo llanta en ventar. Oh wait, wrong beans. I have 4 225/50/18s for sale.

Tirerack has the "original" sizes for the rims im getting, but they only have the Eagle F1's at a decent price. The kumhos were waaaaaay cheaper, but i would have to sacrifice tire height. The guy at the local tire shop told me if i ran 225/45/18 front and 225/40/18 rear, instead of 225/50/18 front and 225/45/18 rear, that it would only be a 3/4" in height difference. He said you probably wouldnt even notice.

It's .8" in the front and a little over an inch in the rear.

Your tires will break loose slight easier, you'll get more fender gap, and for every 20 MPH, you'll be going 19 MPH. Your fuel economy might go up, or it might go down, that depends on whether the energy saved from smaller tires is higher than the extra energy exterted in moving the drive train faster.

so it seems i should invest in the Eagle F1's and get the "original" size, that way i wont have fender gap running a lower profile. I figured if i was moving up an inch in rim diameter, that i can sacrifice tire height and not have gap issues.

Im still curious to see how the 2008 g35 wheels will look on my 2004 sedan. They are the 7 star split spoke wheels.

oh yeah, and it also sucks that they will be staggerd wheels. no tire rotations. That bites. Oh well, thats the price you pay for the sport look.

I don't think you quite get the concept. Just because you're adding an inch to the size of the rims doesn't mean anything is happening to the Overall Diameter of the tire.

If you look, the aspect ratio for each sucessive rim size will get smaller. In other words, the sidewall gets smaller every time the rims gets bigger so that the Overall Diameter stays the same.

So get the Eagle F1s, or buy 2 of the Bridgestones from me and get the other two from Tirerack.

Sentientbydesign wrote: I have 4 225/50/18s for sale.

I see that.

How does one "PM" here? Enlighten me...

dolamite wrote:Whats up everyone? I have a question. I have a 2004 G35 sedan with stock 17's on it. Im upgrading my wheels to the 2008 G35 sedan wheels. The new wheels are 18x7.5 (front) 18x8.5(rear) staggard. It says that the stock sizes for that are 225/50/18 front and 245/45/18 rear. Well with that said the Kumho Ecsta SPT's i want to run they dont carry both sizes. They do have the 225/45/18 for the front and the 245/40/18 for the rear. How much difference in fender gap would it be if i ran the original size compared to the Kumhos i want? Is there a big difference between seeing a 50 series compared to a 45 series on a car? Any bit of info will help. Thanks!

I been doing some research. I think i will fork out the extra money and get the 225/50/18 front and 245/45/18 rear.

PM here is clicking on the profile and emailing

Its be great if we had a PM system set up though....

you dont have to buy tires from tire rack to get a good price man

check out http://www.tiredeals4less.com

look at the TOYO T1R's in those sizes

I'd check and see if you can fit the 245/45/18 on the front rims, if so go with that, else I'd go with the 235/50/18

i was thinking of maybe going with a 225/50/18 front and a 255/45/18 in the rear. the stock rears are 245/45/18. i was gonna go with the 155/45/18 rear.

Beaner wrote:
I see that.

How does one "PM" here? Enlighten me...

Imma you beaner.

NICO has used PM and Email synonymously for quite some time, regardless of it's accuracy.

dolamite wrote:i was thinking of maybe going with a 225/50/18 front and a 255/45/18 in the rear. the stock rears are 245/45/18. i was gonna go with the 155/45/18 rear.

That would work. The rears would only be off by about 1-1.5% versus the original 5%.

the original setup is 225/50/18 front 245/45/18 rear...

can i go 235/50/18 front and 255/45/18 rear without it rubbing or sticking out past the fender walls?

Yes, the issue isn't so much width, but sidewall height.

Both ABS and VDC rely on speed sensors from the wheels, if you go with a tire that is too far off (rotationally) from the front to back ratio you run into problems.

I've read that 3% is a safe limit. I'm currently off by 1% on my coupe, because I run a 255/40/19 opposed to a 245/40/19.

sweet deal. I found some Kumho Ecsta ASX in both sizes on tirerack for a good price. I was just worried about the tires sticking out past the fender wells. 245 to a 255 isnt that much difference.

oooh i forgot, does it matter that these 2008 sedan wheels are going on a 2004 sedan? you think the fender wells and ride hei ghts are different?

When I was buying rims I saw that the 2008 G have a way different offset than the previous gen. Previous gen G35s have very weird offset. I would double check it to make sure it will fit right.

19" G35 coupe rims look great on 04 G sedan. Let me know if you want some pictures.

the dealer and other tire places, said i should have no problems putting 2008 g35 sedan 7 split spoke wheels on my 2004 g35 sedan

Then don't worry so much and got get your new rims and tires

yeah i know. im sorry i was repetetive. i just dont want to get stuck with tires that stick out past the wells of the car. Its for my wifes B-day present.

They shouldn't stick out, should look great.

You're getting her tires for her b-day?

Unless she's a car enthusiast or you're one of those super practical couples, I'd think about something else to go along with it.

I was going to go with the 235/50/18 front and 255/45/18 in rear, and the guy at Tirerack said he couldnt guarantee those would fit, but he said that 235/45/18 front and 255/40/18 rear would fit. I wonder if he told me that because those sizes cost more?