Wheels-Tires Tire sizes. 18x9 front and rear

[Mustang5L5]

What size tires are you guys running with 18x9? More concerned with front, as I can work with the rear once I get the front set.

Not looking to squeeze in massive rubber here.

245/40/18 which would be about the stock 25.6” od

Or 255/35/17 which would run around 25”


Currently running a 235/45/17 which is at 25” and fits well.

 

[KRUISR]

I have 255/35/18 on the front (25.1" OD) which I like because it is shorter than stock and with the 255 width I don't get any rubbing on inner fender.


You can see how it fits on the rim.

 

[Mustang5L5]

Thanks. I think that’s what I’ll run up front.

 

[2000xp8]

I'd think twice about the 255/35/18. It's not enough tire and you need to make the car really low to fill the gap.
It's only 25 inches tall. I ran a 225/40/18 which is pretty much the same height and i hated it.


I switched to a 235/40/18 and honestly that's not enough either. Especially when you are going to probably run a 275/35/18 in the rear.
So now you are lower the front because the gap is too big and you have tall tires in the back.
Not only was the gap too big with the car leveled correctly, but it looked like i had all this meat on the back and rubber on the front.

If i had to do it again, i would go with a 245/40/18 or for you whatever equals that height.
Remember, pony wheels had a 255/55/16 which is like 25.7. That is actually a good height, it's just too much sidewall because of the 16 inch wheels.

Edit: To be clear. I'm more into handling with better ride quality. I'm over the car being in the weeds and the x pipe and front valence scraping on things. I have the car pretty close to what the MM guys suggested for optimum handling.

 

[KRUISR]

My pic above is exactly that tire combo 255/35/18 in front and 275/35/18 in the rear. I have a pair of 285/35/18 I will be putting on soon.

Let me correct your pony wheel size - they were 225/55/16 from the factory.

 

[Mustang5L5]

I already have a 235/45/17 on the front which is 25.0”. So really it would be no difference in OD for me, just width

 

[2000xp8]

Sorry typo, 225/55/16.

Obviously you should do what you prefer. I'm not trying to send you down one of those rabbit holes that your obsession with detail sends you down all the time, but i'm going to anyway, lol.

A 25 on a 17 does not look the same as a 25 on an 18. That extra inch shrinks the tire down to nothing. It very much does look like a rubber band compared to a 275 rear.

I think kruisr's car looks good. But stil i've run similar enough sizes.
On my car, maybe because it's red and a brighter color and my wheels are silver not black it's more noticeable, just for me on my car it looked wrong, really wrong.
Keep in mind i've had 18's since the 90's and i've mixed and matched so many tires that i kinda had to start over figured it out from scratch because of how confusing it was.

Figuring out the rear later sounds risky, i just don't think it's that simple. Not all these sizes are available in every tire brand which could be a problem if you prefer a matching set. Also if you do the 275's in the rear that tire is going to be over half an inch taller, meaning you will have to lower the rear more to get the car to sit right.

I currently have the front fender height at 25.5 and at this moment that's where i plan to leave it. When i had the fender at that height with a 25in tire, the gap was horrible.
If the stock height is 27.25 (maybe you can confirm that) i'm 1.75 lower (which is already quite a bit), 2.25 lower was simply too low for me and while i changed quite a few parts so i couldn't possibly nail down exactly why the car is so much better now, i'd say raising the ride height did have something to do with it.

If i'm coming off as i'm criticizing anyone or their car, i apologize, that's not what i'm attempting to do, it's just a pair of tires is a $500 commitment and i'm not so sure companies let you return them (i've yet to try it). IMO, think in terms of 4 tires and not just getting the front to fit.

If i remember correctly I think @Mstng93SSP got it right with the tire sizes on his 18's and has pics around here somewhere.
Or maybe he will see this and post.

 

[KRUISR]

2000xp8 ... good info. I hadn't thought about fender lip to ground distance, so I went out and measured mine. I got 25.25" in front and 25.5" in the rear.

I have not adjusted the height since that picture so I would expect those numbers should represent what can be seen.

Just adding info to the conversation.

 

[Kid wita 5oh]

245/40/18 in the front

 

[Trogdor]

I've got 245/40/18 on 18x9 SVE Series 1 wheels. The car has Steeda lowering springs and I don't rub.

 

[Mustang5L5]

Ok. I think i will go with 245/40/18. Lets see if i can get the fronts on this week.


Appreciate the advice.

I'll test fit one in the rear to see what I have for space and then can base a rear tire size off that.

 

[Kid wita 5oh]

Ok. I think i will go with 245/40/18. Lets see if i can get the fronts on this week.


Appreciate the advice.

I'll test fit one in the rear to see what I have for space and then can base a rear tire size off that.

I'm running a 285/35/18 in the back but on a 10" wheel, I also don't run the quad shocks... No rubbing at all

 

[Mustang5L5]

I'm sticking with 18x9 in the back as I like the square look. I'd like to get a 255-275 in the rear. I just want to see what I have for clearances first with the 245s and then use that to judge what to do

 

[Mstng93SSP]

Not sure which of my cars we are talking about but this has 275/35/18 rear, and 245/40/18 front. 18x9 Saleen reps and eibach pro kit.

 

[Mustang5L5]

Hows your clearance on the tailpipes out back? Only thing i'm really worried about right now.

 

[AeroCoupe]

Using most tire calculators the 275/35R18 is 25.58" in diameter and the 275/40R17 is 25.88" in diameter so I think comparing a car with either of these tires on the same back spaced wheel would reasonably get the data you are looking for. The actual diameter will vary from manufacturer to manufacturer and will even vary from tire type to tire type within a manufacturer but typically its not a lot. This can be seen in the tire specs on Tire Rack.

I believe your car is stock Fox width on the rear end? If that is the case then my setup will not help as mine is SN95 width and has Nitto NT555 RII 275/40R17's on 17x9 Enkei PF09's with a 45mm offset and 1/8" spacers. No rubbing (sheet metal or tail pipes), no fender lips rolled, the quad shocks are long gone, and Maximum Motorsports LCA's, panhard bar, & torque arm.

Another note is with coil overs, panhard bar, and torque arm you will not run a 10" wide wheel as the way the body of the car articulates over the suspension it will rub unless you do some surgery. The panhard bar is what creates the issue but for the additional handling it was worth it to me.

Again, not sure if my setup helps as I believe we have different width rear ends.

 

[Mustang5L5]

I have a fox lenght axles out back. I moved from the SN95 to accomodate these wheels, which will be 18x9 in the rear. Keeping tailpipes and the panhard bar is on my mind as i know the PNH changes the roll center slightly. I may have to toss a 1/4" spacer on the rear which is fine. Any larger, and i might need to change out my rear studs to accommodate which I'm trying to avoid.

Ordered up a pair of 245/40/18 for the front from local tire shop and will be M&B tomorrow. Gonna stick one in the rear to see what i have for clearance and use that to base my decision on rear tire size.

 

[AeroCoupe]

I will say that the PHB changed my roll center more than a little but my setup is a little different than yours. Cannot wait to see the wheels on the car man, great choice!!!

 

[2000xp8]

Clearance should be fine for the tailpipes with 275's.
My rear sits to the right, measured from the fender on the right to the tire, the tire is about .6 inwards.
On the drivers side it's about a full inch.
For the passenger side i can squeeze my fingers between the exhaust and the tire.
On the drivers side it's way more, probably approaching 1.5 inches or more.
My tailpipes are surely in the right place since i have a saleen rear valence and they have to be centered.

I found that the panhard bar made clearance problems better, not worse.
During hard cornering the rear would move and rub on the inner fender.
Once the PHB was installed, it never happened again.
Though i did install MM extreme lowers to replace my 25 year old steedas that were used back when the car was my daily driver.
Quite possibly that helped too.

I also have the PHB in correctly in a neutral position as they suggest. I can install and remove the rear rod effortlessly, which i had to do because i screwed up and put the short bolt in the wrong side and randomly saw it one day. The bolt and rod easily went in and out.

 

[AeroCoupe]

Guess I need to check my bar then. I had to replace it when I bent the original one (ate a blow out on I-45 in the DFW area) so maybe I f'd that up but the car doesn't seem to handle any different. I had 17x8 Cobra wheels on it then so I would not have noticed much in the way of rubbing like a 17x9. Hope is cools down so I can stand to be in the garage this weekend and check that out.