GT Performance Mods 2005+ Mustang GT Performance and Technical Information

255/45s or 275/40s

Thread Tools
 
Search this Thread
 
Old Jan 9, 2008 | 12:55 AM
  #1  
TMac's Avatar
Thread Starter
Member
 
Joined: July 22, 2007
Posts: 14
Likes: 0
255/45s or 275/40s

Looking at either width all around for 18s, is there going to be much of a handling difference (Nitto 555s) between the 2 sizes or just cosmetic having meatier tires? Thanks.
Reply
Old Jan 9, 2008 | 12:58 AM
  #2  
Enfynet's Avatar
 
Joined: August 19, 2004
Posts: 2,047
Likes: 3
From: Cleveland
I would imagine the 275 would offer slightly better grip, but they are smaller overall diameter by about 1/2" Unless you have a tune your speedometer will be off slightly [nothing dramatic, but not accurate]
Reply
Old Jan 9, 2008 | 05:36 AM
  #3  
tom281's Avatar
Legacy TMS Member
 
Joined: October 8, 2005
Posts: 12,395
Likes: 29
From: Medina county, OH
I run 275/40/18 Nitto 555's on all four corner...... this is on 18x9" wheels. What size of wheels do you have?
Reply
Old Jan 9, 2008 | 08:36 AM
  #4  
TMac's Avatar
Thread Starter
Member
 
Joined: July 22, 2007
Posts: 14
Likes: 0
I am looking to buy American Muscle's GT4s, 18x9. Do you find the 275s follow ruts in the road?
Reply
Old Jan 9, 2008 | 10:43 AM
  #5  
tom281's Avatar
Legacy TMS Member
 
Joined: October 8, 2005
Posts: 12,395
Likes: 29
From: Medina county, OH
Originally Posted by TMac
I am looking to buy American Muscle's GT4s, 18x9. Do you find the 275s follow ruts in the road?
Maybe more so than the factory tires did; however it's not an issue around here plus they handle so much better than factory.
Reply
Old Jan 9, 2008 | 11:14 AM
  #6  
Five Oh Brian's Avatar
Tasca Super Boss 429 Member
 
Joined: November 14, 2007
Posts: 3,651
Likes: 8
From: Pacific NW USA
Originally Posted by TMac
I am looking to buy American Muscle's GT4s, 18x9. Do you find the 275s follow ruts in the road?
I ran 275's all the way around my 2003 Mach 1 and it tracked badly in the ruts - noticably worse than the factory 245's. However, I will not hesitate to replace the factory 235's on my 07 Mustang GT with something wider. I'll likely go 245's in the front and 265's in the back (on my 18 x 8.5 factory fan blades). With an 18 x 9 wheel, a 275 width tire would be great.
Reply
Old Jan 9, 2008 | 07:43 PM
  #7  
Gene K's Avatar
Mach 1 Member
 
Joined: December 24, 2007
Posts: 563
Likes: 0
Originally Posted by Enfynet
I would imagine the 275 would offer slightly better grip, but they are smaller overall diameter by about 1/2" Unless you have a tune your speedometer will be off slightly [nothing dramatic, but not accurate]
Mines off by nearly 5 mph from the factory. Tach is spot on but the mph is off. Almost seems like the factory PCM is set for 3.31 instead of 3.55.
One of these days Im going to flash it with 3.55 instead of stock with my X3 and see if it changes mph per rpm registered.
Reply
Old Jan 10, 2008 | 12:59 AM
  #8  
eddieval5's Avatar
GT Member
 
Joined: April 26, 2007
Posts: 123
Likes: 0
From: katy,tx
if your looking for a pic ill be getting with this wheel set up tommorrow(hopefully) and will take pics.
Reply
Old Jan 10, 2008 | 08:06 AM
  #9  
TMac's Avatar
Thread Starter
Member
 
Joined: July 22, 2007
Posts: 14
Likes: 0
Please do, thanks.
Reply
Old Jan 10, 2008 | 06:07 PM
  #10  
eddieval5's Avatar
GT Member
 
Joined: April 26, 2007
Posts: 123
Likes: 0
From: katy,tx
okay i got my wheels but its to dark to take get any good shots but will have some up tommorrow morning
Reply
Old Jan 10, 2008 | 06:16 PM
  #11  
65sohc's Avatar
Bullitt Member
 
Joined: December 28, 2004
Posts: 398
Likes: 0
Originally Posted by Gene K
Mines off by nearly 5 mph from the factory. Tach is spot on but the mph is off. Almost seems like the factory PCM is set for 3.31 instead of 3.55.
One of these days Im going to flash it with 3.55 instead of stock with my X3 and see if it changes mph per rpm registered.
In your flasher there should be an option for tire revolutions per mile which will correct your speedo. The revs per mile is available in the Tire Rack specs for your tires.
Reply
Old Jan 12, 2008 | 11:01 AM
  #12  
bored out's Avatar
Bullitt Member
 
Joined: May 25, 2007
Posts: 463
Likes: 0
From: Robins AFB
Tom, how is the grip on those NITTO's and are you happy with the 275's?
Reply
Old Jan 12, 2008 | 04:27 PM
  #13  
tom281's Avatar
Legacy TMS Member
 
Joined: October 8, 2005
Posts: 12,395
Likes: 29
From: Medina county, OH
I love the Nittos..... I was a little hesitant to try them but I'm very glad that I did. Traction, well that's maybe not the fairest question- with the blower and 4.10 rear gears you have to learn to drive the car nicely in the first 3 gears LOL but overall they're pretty dang good IMO.
Reply
Old Jan 12, 2008 | 06:55 PM
  #14  
bored out's Avatar
Bullitt Member
 
Joined: May 25, 2007
Posts: 463
Likes: 0
From: Robins AFB
Ya, that is some problem to have ! Thanks bro!
Reply
Old Jan 12, 2008 | 11:42 PM
  #15  
fazerxx's Avatar
Member
 
Joined: August 21, 2006
Posts: 21
Likes: 0
I'm running Nitto 555s, 295 in back 255 in front. Rims are 18x10 fr and 18x9 rear. Much better handling than stock, no following ruts either.
Attached Thumbnails 255/45s or 275/40s-copy-dsc00142-large-.jpg  
Reply
Old Jan 13, 2008 | 06:26 AM
  #16  
Mach's Avatar
Mach 1 Member
 
Joined: November 30, 2006
Posts: 571
Likes: 1
From: Columbia, Missouri
I run 275/40/18's on 18x9's all the way around and have had no problems with tracking.

Currently have ContiExtremeContact All Season, and don't recommend them for twisty handling traction in dry conditions. They are very soft and squeel pretty bad. I do say they handle snow and ice quite well, and since that is where we are now, that is a good thing. Even in HEAVY rain they are outstanding, so I suppose you can't have everything.

I am shopping for my "spring shoes" right now...
Reply
Old Jan 13, 2008 | 02:54 PM
  #17  
eddieval5's Avatar
GT Member
 
Joined: April 26, 2007
Posts: 123
Likes: 0
From: katy,tx
okay finally got a pic from my cell though so quality isnt very good. sorry couldnt find my cable to digital camera.

anyways here you go:
Reply
Old Jan 13, 2008 | 03:45 PM
  #18  
antdog's Avatar
Mach 1 Member
 
Joined: March 22, 2005
Posts: 503
Likes: 0
Originally Posted by eddieval5
okay finally got a pic from my cell though so quality isnt very good. sorry couldnt find my cable to digital camera.

anyways here you go:
Dad, could I have the keys please? I want to take it for a spin. Could you hook a brother up!
Reply
Old Jan 13, 2008 | 04:23 PM
  #19  
eddieval5's Avatar
GT Member
 
Joined: April 26, 2007
Posts: 123
Likes: 0
From: katy,tx
Originally Posted by antdog
Dad, could I have the keys please? I want to take it for a spin. Could you hook a brother up!
Dad? wtFFF..lol..hes my nephew no kids for this 20 year old..haha
Reply
Old Jan 13, 2008 | 04:35 PM
  #20  
TMac's Avatar
Thread Starter
Member
 
Joined: July 22, 2007
Posts: 14
Likes: 0
Those are sweet a$$ wheels, thanks for the pics
Reply



All times are GMT -6. The time now is 01:43 AM.