Comparison on 99 Mustang GT, 275/40zr17 vs 245/45zr17 - Forums at Modded Mustangs
 5Likes
Reply
 
LinkBack Thread Tools
post #1 of 34 Old February 10th, 2016, 04:49 AM Thread Starter
Regular
 
KB99GT's Avatar
 
Join Date: Nov 2010
Location: Georgia
Posts: 128
 
iTrader: 0 reviews
Comparison on 99 Mustang GT, 275/40zr17 vs 245/45zr17

Looking for opinions. I have OEM ordered with the car (and thus, painted to match) 17x9 cobra rims on a 99 GT. They came with 275/40's, I just put Uniroyal Tiger Paw GTZ 245/45zr17's on it. Did I F up or is this a good selection for a DD? Ford Racing B spring drop when i bought it. Only mod done to it before i bought it 5yr ago. Had Michelin Pilot Sport 275/40zr17's on it dried out bad even from the get go, just ran them until they started cracking to dangerous levels. So far, the Uniroyals ride smoother and track well on the car. Stick well and I no longer have the dried out lack of grip, but, I know there's a wealth of knowledge here.
KB99GT is offline  
Sponsored Links
Advertisement
 
post #2 of 34 Old February 10th, 2016, 09:47 AM
US Air Force (retired)
 
Eagle2000GT's Avatar
 
Join Date: Aug 2007
Location: Indiana
Posts: 13,518
                     
Garage
iTrader: 1 reviews
You didn't mess up exactly. A 245/45-17 tire is suppose to fit on 7.5-9" wheels. So safety wise you are OK. I've run them on 9" wheels before. They look stretched and I didn't care much for the look. Tires stretched to the max offer no curb rash protection. I also had a bit of trouble with the outer edges of the tires wearing out first. Stretching the sidewall out pushes the edges of the tread down.

A 245/40-17 has the same sidewall height as a 245/45 (110 mm) so it doesn't throw off your speedometer. They are supposed to fit 9-11" wheels but I've had them on 10.5" wheels and they really looked stretched. So much so that I bought an extra pair of 9" wheels for my winter all-season tires.

Here is a tire/wheel calculator that I use:
Tire Size Calculator - Tire & Wheel Plus Sizing

ProCharger P-1SC, 9 psi, STD 396/383; Uncorrected 388/375; SAE 383/370.
Ret. USAF 1969-1973,1980-1996: Vietnam veteran. Aircraft maintenance. R & D, ICBM Operations.
Also own: 1997 Harley FXDWG, 1998 F-150, and 2002 Corvette LS1
Eagle2000GT is offline  
post #3 of 34 Old February 10th, 2016, 10:42 AM
I Post Entirely Way Too Much
 
maxgst's Avatar
 
Join Date: Jun 2010
Location: Miami, Fl
Posts: 5,648
               
iTrader: 2 reviews
On my other car im running 235/40 on a 10 inch wheel (at least until I get wider fenders and can fit a wider tire), and I have friends running 225 on a 10 inch wheel, so safety wise you are clear.

What you might be lacking is grip.


2000 Mustang GT vert - Gone
2002 Mustang GT coupe - Sold on 12/20/17
2007 BMW 335i
1994 BMW 328i - Foxbody 5.0 Swap
maxgst is offline  
Sponsored Links
Advertisement
 
post #4 of 34 Old February 10th, 2016, 11:05 AM
Enthusiast
 
Join Date: Jun 2011
Posts: 511
         
iTrader: 0 reviews
245 on a 9 inch wheel will look dumb, IMO.

8 inch wheel = 245
9 inch wheel = 275
10.5 inch wheel = 315

That will leave the sidewall relatively straight with no stretch, and possibly just a touch of bulge depending on the exact brand and how wide they run. My 275 Nittos were straight, and my current 275 BFGs bulge ever so slightly. Looks great.
Eagle2000GT likes this.

-Will


sneaky98gt is offline  
post #5 of 34 Old February 10th, 2016, 04:41 PM
Enthusiast
 
akurma's Avatar
 
Join Date: Nov 2013
Location: Pennsylvania
Posts: 921
 
iTrader: 3 reviews
Quote:
Originally Posted by sneaky98gt View Post
245 on a 9 inch wheel will look dumb, IMO.

8 inch wheel = 245
9 inch wheel = 275
10.5 inch wheel = 315

That will leave the sidewall relatively straight with no stretch, and possibly just a touch of bulge depending on the exact brand and how wide they run. My 275 Nittos were straight, and my current 275 BFGs bulge ever so slightly. Looks great.
x2 with the "bulge" depending on brand. 315 Mickey Thompson's bulge a bit but i've seen other brand 315's with no bulge
akurma is offline  
post #6 of 34 Old February 10th, 2016, 07:37 PM
I Post Entirely Way Too Much
 
blownstang's Avatar
 
Join Date: Jun 2010
Location: Chicago, IL
Posts: 6,972
                 
iTrader: 2 reviews
I run a BFG 255 on my 9" front wheels. Its slightly more of a stretch than i expected. I wouldnt put a 245 on just because of how it would look.
blownstang is offline  
post #7 of 34 Old February 10th, 2016, 08:39 PM
Nile P. Pezdel of Pez Dispenser Inc. CCA
 
nileppezdel77!'s Avatar
 
Join Date: Dec 2010
Location: Brooklyn
Posts: 5,502
               
Garage
iTrader: 3 reviews
Quote:
Originally Posted by maxgst View Post
I have friends running 225 on a 10 inch wheel.

Yikes...

Eagle2000GT and sneaky98gt like this.



'01 GT Convertible
Maximum Motorsports TQA|PHB|FLSFC|LCA|Coilovers
D&D T56 Magnum; Cobra R Brakes; Sparco Seats
Tuned by Mustang Magic and so much other stuff

'16 Fiesta ST
Cobb FMIC, Turbo-back exhaust, RMM and Air Filter
Tuned by Stratified
nileppezdel77! is offline  
post #8 of 34 Old February 10th, 2016, 08:40 PM
Enthusiast
 
Join Date: Jun 2011
Posts: 511
         
iTrader: 0 reviews
Quote:
Originally Posted by akurma View Post
x2 with the "bulge" depending on brand. 315 Mickey Thompson's bulge a bit but i've seen other brand 315's with no bulge
Yup, my 275/40-17 MT ET Street Radials bulge quite a bit on my extra set of track wheels (also 17x9). That being said, I wouldn't go down in size over what I posted above because of it. It definitely looks and performs better if it's a little oversized vs. undersized, and I'd consider those numbers I posted above to be minimums.

-Will


sneaky98gt is offline  
post #9 of 34 Old February 10th, 2016, 08:48 PM
The Dude Abides
 
1MeanNonPI2v's Avatar
 
Join Date: Feb 2014
Location: 93,000,000 Miles from the sun
Posts: 1,471
   
Garage
iTrader: 0 reviews
I wouldn't run anything less than a 275 on a 9" wide wheel. You get much better turn in response and braking with the wide front tires too.



"Yeah, well, you know, that's just, like, your opinion, man." - The Dude

"If you can't hear it before you see it, what's the point?" - Jesse James
1MeanNonPI2v is offline  
post #10 of 34 Old February 10th, 2016, 11:16 PM
US Air Force (retired)
 
Eagle2000GT's Avatar
 
Join Date: Aug 2007
Location: Indiana
Posts: 13,518
                     
Garage
iTrader: 1 reviews
I run 275/40-17 Continental ExtremeContact DWS on my 9" wheels. They look and perform well. I have run 245/45-17 Continental ExtremeContact DWS on the same wheels. I won't do it again.

ProCharger P-1SC, 9 psi, STD 396/383; Uncorrected 388/375; SAE 383/370.
Ret. USAF 1969-1973,1980-1996: Vietnam veteran. Aircraft maintenance. R & D, ICBM Operations.
Also own: 1997 Harley FXDWG, 1998 F-150, and 2002 Corvette LS1
Eagle2000GT is offline  
post #11 of 34 Old February 10th, 2016, 11:20 PM
Regular
 
Join Date: Nov 2015
Posts: 465
 
iTrader: 0 reviews
Post some pics man. I was debating about 17x9s and running my 245s for now.
2k2wranglerx is offline  
post #12 of 34 Old February 11th, 2016, 10:14 AM
I Post Entirely Way Too Much
 
maxgst's Avatar
 
Join Date: Jun 2010
Location: Miami, Fl
Posts: 5,648
               
iTrader: 2 reviews
Lol, Mustang people be way too uptight, throwing accusations without any real world experience.

this is 225 on a 9.5 (My ex roommate)


This my my other roommate, with the 225 on 10 inch rim I was talking about


I'm not saying it looks good, but they both have been running that set up for a long ass time, and never had any issues. so 245 on a 9 inch rim is totally fine.


2000 Mustang GT vert - Gone
2002 Mustang GT coupe - Sold on 12/20/17
2007 BMW 335i
1994 BMW 328i - Foxbody 5.0 Swap
maxgst is offline  
post #13 of 34 Old February 11th, 2016, 11:44 AM
Anandavenkatakrishnan
 
dsgpony's Avatar
 
Join Date: Jun 2012
Location: The Mitten
Posts: 21,385
                   
iTrader: 1 reviews
Quote:
Originally Posted by 1MeanNonPI2v View Post
I wouldn't run anything less than a 275 on a 9" wide wheel. You get much better turn in response and braking with the wide front tires too.

If you're looking for better turn in, I would actually put a 255/265 on the front with a lower profile (35 series) and turn the camber down.




Sent from AutoGuide.com Free App

[/CENTER]
2.3L Roush Supercharger/20" Staggered Niche Milan Wheels/H&R Coil Overs
Kooks Longtubes/Catted X/Magnaflow Competition Catback
dsgpony is offline  
post #14 of 34 Old February 11th, 2016, 12:30 PM
The Dude Abides
 
1MeanNonPI2v's Avatar
 
Join Date: Feb 2014
Location: 93,000,000 Miles from the sun
Posts: 1,471
   
Garage
iTrader: 0 reviews
Quote:
Originally Posted by dsgpony View Post
If you're looking for better turn in, I would actually put a 255/265 on the front with a lower profile (35 series) and turn the camber down.




Sent from AutoGuide.com Free App
The narrower tire won't out brake the 275. And the 275 will still have a larger contact patch in the turns. The 275 is superior to the 255 IMO.

I've had a 245, 255 and a 275 on the front of my cars. 275 is hands down my favorite and it absolutely fits a 9" wide wheel the best.



"Yeah, well, you know, that's just, like, your opinion, man." - The Dude

"If you can't hear it before you see it, what's the point?" - Jesse James
1MeanNonPI2v is offline  
post #15 of 34 Old February 11th, 2016, 06:39 PM
I Post Entirely Way Too Much
 
blownstang's Avatar
 
Join Date: Jun 2010
Location: Chicago, IL
Posts: 6,972
                 
iTrader: 2 reviews
I bought my car with a 275 up front and went to a 255. I didnt want that big of a tire up front. It feels much better. The 255 BFG is flush with the lip and offers little curb rash protection. A 245 would definitely have the lip sticking out. I wouldnt do 245 just because of the ricer look.
blownstang is offline  
post #16 of 34 Old February 11th, 2016, 08:58 PM
The Dude Abides
 
1MeanNonPI2v's Avatar
 
Join Date: Feb 2014
Location: 93,000,000 Miles from the sun
Posts: 1,471
   
Garage
iTrader: 0 reviews
Well I just mounted my new Toyo R888 275/40R17 front and 315/30R18 rears and it looks spectacular. Tires are super sticky, haven't done anything crazy to really test them out. I'll never go away from a 275 in front of a 94-04 unless I go slick and skinnies.



"Yeah, well, you know, that's just, like, your opinion, man." - The Dude

"If you can't hear it before you see it, what's the point?" - Jesse James
1MeanNonPI2v is offline  
post #17 of 34 Old February 11th, 2016, 09:50 PM Thread Starter
Regular
 
KB99GT's Avatar
 
Join Date: Nov 2010
Location: Georgia
Posts: 128
 
iTrader: 0 reviews
I personally love the 245's, especially the grip for an all season tire. Grips better than the 275's ever did, bit taller though, and with the b spring/no isos on the front....gotta watch big bumps. Outside of that, it corners better, and where i usually go hard from a stop, and always ended up sideways going from 1/2 it just has a light chirp going to 2nd. Width difference is barely noticable, and very very little bulge. heck, the 275's bulged more, probably due to the dry-rot. By the way, these are stock tire size for OEM cobra rims from 99, which is what this has on it. Overall, very pleased with the choice.
KB99GT is offline  
post #18 of 34 Old February 11th, 2016, 11:32 PM
Corner Carvin
 
Join Date: Oct 2015
Posts: 149
 
Garage
iTrader: 0 reviews
Quote:
Originally Posted by maxgst View Post
Lol, Mustang people be way too uptight, throwing accusations without any real world experience.

this is 225 on a 9.5 (My ex roommate)


This my my other roommate, with the 225 on 10 inch rim I was talking about


I'm not saying it looks good, but they both have been running that set up for a long ass time, and never had any issues. so 245 on a 9 inch rim is totally fine.
Nobody is throwing accusations, they are throwing truths. Just because a bunch of stance nation idiots run stretched out tires doesnt make it advisable.

Tires are meant to fit specific wheel sizes based off the tire widths. It's not fiction.
Eagle2000GT and 1MeanNonPI2v like this.

99 cobra- Slow
JCP281 is offline  
post #19 of 34 Old February 12th, 2016, 12:21 AM
I Post Entirely Way Too Much
 
blownstang's Avatar
 
Join Date: Jun 2010
Location: Chicago, IL
Posts: 6,972
                 
iTrader: 2 reviews
Quote:
Originally Posted by KB99GT View Post
I personally love the 245's, especially the grip for an all season tire. Grips better than the 275's ever did, bit taller though, and with the b spring/no isos on the front....gotta watch big bumps. Outside of that, it corners better, and where i usually go hard from a stop, and always ended up sideways going from 1/2 it just has a light chirp going to 2nd. Width difference is barely noticable, and very very little bulge. heck, the 275's bulged more, probably due to the dry-rot. By the way, these are stock tire size for OEM cobra rims from 99, which is what this has on it. Overall, very pleased with the choice.
99 cobra wheels are 17x8. You mentioned 17x9 in your first post?
blownstang is offline  
post #20 of 34 Old February 12th, 2016, 09:33 AM
New time's coming soon!!!
 
CJackson's Avatar
 
Join Date: Feb 2013
Location: Corbin, KY
Posts: 3,008
           
Garage
iTrader: 9 reviews
I never noticed a difference going from a 245 to a 275. It isn't going to matter. Then when I swapped to skinnys I honestly still didn't notice much when it comes to braking. But obviously I did when it came to turning, even then it isn't near as bad as some people put it out to be.



My Build Thread : https://www.moddedmustangs.com/forums...-gt-build.html

D1SC 12-13psi 391rwhp 411rwtq
CJackson is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Forums at Modded Mustangs forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome