THE Tire Thread


What Combo Do You Use?


  • Total voters
    262

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
 
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enrico

GT Owner
Jul 20, 2010
70
London, UK
Pirelli rears are still there (345/35R19) but they cost more than twice the bridgestone!
 

2112

Blue/white 06'
Mark II Lifetime

What is the difference between the two different Bridgestones listed for the front?
 

2112

Blue/white 06'
Mark II Lifetime
Well, I want the tires for this season so I pulled the trigger on the 265/40 and 345/35 Bridgestones. Y rating is the highest speed rating from the Tirerack site info page.

They said they were in stock and shipping from Reno. They took my $ so I hope there are no glitches.
 

kmillen

Well-known member
Jan 29, 2007
504
What sizes Kyle?

Michelin Pilot sport cup tires in sizes:

Rear- 345z30ZR19
Front-235/40ZR18

They were in stock at Michelin.
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
What are the pros and cons for going with the 255 vs. the 265 on the front. Since the stocks are only 235 I would think that the 255 would be best, but most have gone with the 265s.
 

SteveA

GT Owner/B.O.D
Mark IV Lifetime
Dec 13, 2005
3,694
Sandpoint Id
I went with 255 (19's) in the front rather than the 265's because I didn't want the larger diameter.
 

HiloDave

GT Obsessed
Mark II Lifetime
Dec 7, 2005
928
Hilo, Hawaii
Y rating is the highest speed rating from the Tirerack site info page.

Can someone please explain the difference between R and ZR speed ratings? Are R's safe at 200 mph? Is is safe to have R's on the front and ZR's on the back?
 

paul b

GT Owner
Nov 2, 2006
810
ZR should mean 149mph and it's a radial
 

2112

Blue/white 06'
Mark II Lifetime
Beginning in 1991, the speed symbol denoting a fixed maximum speed capability of new tires must be shown only in the speed rating portion of the tire's service description, such as 225/50R16 89S. The most common tire speed rating symbols, maximum speeds and typical applications are shown below:

L 75 mph 120 km/h Off-Road & Light Truck Tires
M 81 mph 130 km/h
N 87 mph 140km/h Temporary Spare Tires
P 93 mph 150 km/h
Q 99 mph 160 km/h Studless & Studdable Winter Tires
R 106 mph 170 km/h H.D. Light Truck Tires
S 112 mph 180 km/h Family Sedans & Vans
T 118 mph 190 km/h Family Sedans & Vans
U 124 mph 200 km/h
H 130 mph 210 km/h Sport Sedans & Coupes
V 149 mph 240 km/h Sport Sedans, Coupes & Sports Cars

When Z-speed rated tires were first introduced, they were thought to reflect the highest tire speed rating that would ever be required, in excess of 240 km/h or 149 mph. While Z-speed rated tires are capable of speeds in excess of 149 mph, how far above 149 mph was not identified. That ultimately caused the automotive industry to add W- and Y-speed ratings to identify the tires that meet the needs of new vehicles that have extremely high top-speed capabilities.

W 168 mph 270 km/h Exotic Sports Cars
Y 186 mph 300 km/h Exotic Sports Cars
 

GT4JR

GT Owner
Mark II Lifetime
Jul 26, 2006
189
Yorba Linda, California
I am using now after market tires.
 

2112

Blue/white 06'
Mark II Lifetime
What are the pros and cons for going with the 255 vs. the 265 on the front. Since the stocks are only 235 I would think that the 255 would be best, but most have gone with the 265s.

I went with the 265 for the extra width. In an 18" they are only .25mm taller than stock
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,194
I went with 255 (19's) in the front rather than the 265's because I didn't want the larger diameter.

Hey Steve, they actually stepped down aspect ratio to maintain OEM-like diameters. The OEM front is a 235/45-18 with a diameter of 26.33". If you go with the Bridgestones you can get either a 255/40-18 with a diameter of 26.03, or you can get a 265/40-18 with a diameter of 26.35" So, you are correct in that the 255 are smaller, but the 265's actually are much closer to the OEM Goodyear diameter (.02" difference).
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
I got this answer back from Goodyear today, but it really doesn't answer the question. Obviously there are a few tires somewhere out there (TireRack doesn't have any), but the question of a production run is not mentionsed.

From: goodyear_cr@goodyear.com on 01/20/2011 04:51 PM

Sent by: Goodyear Tire & Rubber Company Consumer Relations 728 1144 East
Market Street Akron, OH 44316 Voice #: 800.321.2136 Fax #:
330.796.6829

Hi Mr Lehotsky,

We show some availability of the Eagle F1 SuperCar tire in both sizes. if
you would like assistance in locating the tires, please contact our
Consumer Relations Department at 1-800-321-2136. We are available Monday
through Friday from 8:15 AM through 5:15 PM.

The product code for the 235/45ZR18 is 389-024-128

The product code for the 315/40ZR19 is 389-025-128


Barbara Hummel
Consumer Relations
 

MTV8

GT Owner
Mark II Lifetime
Jul 24, 2010
1,017
Houston Texas
WTF is everyone doing about the lack of tires for our cars? Kendall informed me that not only are our Goodyears not available, neither are the Bridgestones.

My Goodyear rears are down to 4/32 and I am running at Mojave in April so I am definitely in the market for some rubber.

The tire rack website shows the bridgestones in stock.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,194
The Bridgestones went out of stock for approximately a 10-day window at Tire Rack over the Holidays. It appears to be a genuine out of stock because now that supply has returned, the new Bridgestones have VERY recent date codes. They are currently showing as available from Tire Rack and I have a new set here awaiting install on my car if anyone's in a pinch.
 

PHXGT

GT Owner
Mark II Lifetime
Sep 11, 2005
369
Phoenix, AZ
Anyone hear of a new stickier Goodyear that is supposed to be coming out?
 

Fubar

Totally ****** Up
Mark II Lifetime
Le Mans 2010 Supporter
Aug 2, 2006
3,979
Dallas, TX
Anyone hear of a new stickier Goodyear that is supposed to be coming out?

Are you talking about the Goodyear Eagle F1 Supercar: G2?

Doesn't fit the GT. I think it is stock on the GT500 or something.
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
I sent this e-mail to Goodyear this afternoon:

Dear Ms. Hummel,

Thank you for your assistance in locating the 235/45ZR18 and 315/40ZR19 tires. I have passed this information on to the other owners of Ford GT SuperCars via the www.fordgtforum.com

However, a major concern of all of us is the most recent date of manufacture. It seems like no one has been able to find any tires with a manufacturing date later than November, 2006. This is a bit disturbing, as (1) such tires are already over 4 years old, and (2) at such an age, would they still be a reliable tire to take to speeds in excess of 200 mph? Most of us are reluctant to press such tires toward their upper speed limits. As such, they are rapidly approaching the six year life of tires that most manufacturer's recommend. In fact, the rear tires that I was able to find last October were dated 2604, indicating a manufacturing date of the last week of June, 2004. These tires are already over 6½ years old! Clearly, it would seem time to produce a new run of these tires, especially as quite a few owners like to track their vehicles at rather fast race tracks around the USA.

A quote I found recently states:

"In a statement from the British Rubber Manufacturers Association (BRMA) issued on June 5, 2001 regarding the age of tires they state, 'BRMA members strongly recommend that unused tires should not be put into service if they are over 6 years old and that all tires should be replaced 10 years from the date of their manufacture.' ... the worst part is that you cannot tell the safety of an old tire just by looking at it since there are no conclusive tests for the safety of tires without destroying the tire itself! ...The more aggressive its compound … the shorter tire life." (Ref 1)

Thank you for my indulgence.

Yours very truly,

Ralph B. Lehotsky

cc: www.fordgtforum.com

Reference 1: http://searchwarp.com/swa59705.htm
 

2112

Blue/white 06'
Mark II Lifetime
My Bridgestones arrived. Boy are they light and supple. They are not as sticky to my hands as the P Zeros I have on another car though. I am looking forward to driving them and finally filling the wheel wells a bit more.
 
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