Rim / tire size question


Justin

GT Owner
Jun 30, 2013
27
Massachusetts
Anybody have any experience or advice on putting a set of HRE rims on an otherwise mainly stock GT that are 20" front and 21" rear? The tires on them are Michelin 255/35/20 front 325/35/21 rear. The prior owner says they bolted on to his car no issue, and his car was stock as well. Any thoughts or comments are appreciated. Thanks.

J
 

STORMCAT

GT
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May 25, 2006
7,549
Ft. Lauderdale
If he says they will fit because they have the proper offset you have to trust him on that. Most wheels are built to custom specs.
The thing to consider are : 1) make sure the OD of the tires is close to the OEM Goodyear tires so your Speedo and ABS are in a close range. 2) The problem I have with going to a 20/ 21 is you are giving up a lot of tire side wall height. The flex in tire side wall height is what gives you some cushioning and protection from harsh road bumps and pot holes etc.. could be a teeth rattling ride if the roads are not glass smoothe.. 3) Consider the weight. typically the larger wheels are heavier and the increase in rotational mass will affect the acceleration and braking to the negative side.
 

Justin

GT Owner
Jun 30, 2013
27
Massachusetts
Thanks Stormcat, good points. He gave me these measurements with the tires off the car: front tire are 26.5 and rear are 28". I'm not sure what the typical GT tire/rim diameter is since my 'new' GT is in transit to me at the moment. The seller says that when he had them on the car he felt the ride height difference was about 1/4" taller. Thanks again.
 

Xcentric

GT Owner
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Jul 9, 2012
5,213
Myakka City, Florida
See post 477 of this thread http://www.fordgtforum.com/forums/showthread.php/12372-THE-Tire-Thread/page48 for diameters and weights of OEM Goodyears and replacement Bridgestones on base and optional wheels.

I would weigh what you have and not add rotating mass.
 

STORMCAT

GT
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May 25, 2006
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Thanks Stormcat, good points. He gave me these measurements with the tires off the car: front tire are 26.5 and rear are 28". I'm not sure what the typical GT tire/rim diameter is since my 'new' GT is in transit to me at the moment. The seller says that when he had them on the car he felt the ride height difference was about 1/4" taller. Thanks again.

OEM tires as Follows : OD of the rear Good Years are 28.9 " The OD front Good years are 26.32"
So what he has is slightly larger OD in the front but almost an 1" smaller in the rear. That changes the rake and the look of the car. A 1" small OD in the rear is fairly significant. For the record the Bridgestone 345/35/19 has and OD of 28.6" it's not as tall as the OEM tire but it's a close and a good tire that's why most people use it. also keep in mind it's a 19" wheel vs a 21" wheel you give up 2" plus of side wall with the 21" wheel..

The tire rack has some great tools to compare sizes ,OD's, weights ( RPM = revs per mile ) the old charts use to tell you if the tire was out of the acceptable range of diameter dimension differential.. I think it was 2%... Early on when engineering my brake and wheel package I can tell you I spent countless hours looking at tire dimensions , OD diameters and weights etc.. The GT rear tires are some of, If not the tallest / largest OD high performance tires put on a car.

If I was going to shop for a new set of rims and tires today I would go 19" front and 20" rear.. There are some good 315/35/20 rear tires out there that spec out at ( 28.7" OD ) and some 19" fronts in various sizes that are close to the OEM 26.32" OD . I have 19" wheels in front to clear my brakes. I use a 245/35/19 on the front and I wouldn't want less of a side wall and I live in FL with glass smooth roads.. Giving up an inch of side wall on a 20' front wheel and tire conbo in your NE area would probably be a really rough ride.. maybe that's why he is selling them.. :biggrin That's my 2cents
 
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Justin

GT Owner
Jun 30, 2013
27
Massachusetts
Thanks again Stormcat. The seller sold his GT but kept the rims and is selling them now. HRE 'custom' made them for his GT. He sent me some pictures with them on the car, they looked good. But your point about ride is certainly a good consideration. I agree with your thought that a 19/20 setup is nice, I'm just considering these because the price point is only $4k for low mile tires plus the rims. Thanks again for the detailed info storm and link Xcentric.
 

roketman

GT Owner
Mark IV Lifetime
Oct 24, 2005
7,996
ma.
Anybody have any experience or advice on putting a set of HRE rims on an otherwise mainly stock GT that are 20" front and 21" rear? The tires on them are Michelin 255/35/20 front 325/35/21 rear. The prior owner says they bolted on to his car no issue, and his car was stock as well. Any thoughts or comments are appreciated. Thanks.

J

Where are you in Ma?Specracer and myself are also in Ma
 

Justin

GT Owner
Jun 30, 2013
27
Massachusetts
Westborough, where you guys at?
 
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STORMCAT

GT
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May 25, 2006
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Ft. Lauderdale
Thanks again Stormcat. The seller sold his GT but kept the rims and is selling them now. HRE 'custom' made them for his GT. He sent me some pictures with them on the car, they looked good. But your point about ride is certainly a good consideration. I agree with your thought that a 19/20 setup is nice, I'm just considering these because the price point is only $4k for low mile tires plus the rims. Thanks again for the detailed info storm and link Xcentric.

No problem .. Roketman and Specracer are good guys to know.. some of the best (self proclaimed) Massholes I know !! :biggrin
 

fjpikul

GT Owner
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Jan 4, 2006
11,475
Belleville, IL
The Kitty lets out his claws.
 

roketman

GT Owner
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Oct 24, 2005
7,996
ma.
I am in Acton
Andy is Duxbury
Pm me and I will give you my contact info
 

Saint Ho

GT Owner
Feb 12, 2013
481
Paris FRANCE
Anybody have any experience or advice on putting a set of HRE rims on an otherwise mainly stock GT that are 20" front and 21" rear? The tires on them are Michelin 255/35/20 front 325/35/21 rear. The prior owner says they bolted on to his car no issue, and his car was stock as well. Any thoughts or comments are appreciated. Thanks.

J
Good morning.
I mounted HRE wheels on my car.
The tires are Michelin Supersport Pilot, 245 x 35 x 19 at the front, and 345 x 30 x 20 at the rear.
Not only is there no problem, but most of all, my Ford GT has become MUCH MORE NICE TO DRIVE.
(The decoration on the tires is not original. I did it).

IMG_0092.jpg
 

Specracer

GT Owner
Mark IV Lifetime
Nov 28, 2005
7,081
MA
Hey.... I resemble that remark.....

some of the best (self proclaimed) Massholes I know !! :
 

2112

Blue/white 06'
Mark II Lifetime
Good morning.
I mounted HRE wheels on my car.
The tires are Michelin Supersport Pilot, 245 x 35 x 19 at the front, and 345 x 30 x 20 at the rear.
Not only is there no problem, but most of all, my Ford GT has become MUCH MORE NICE TO DRIVE.
(The decoration on the tires is not original. I did it).

View attachment 45760


How did you apply the white letters?
 

STORMCAT

GT
Mark IV Lifetime
Le Mans 2010 Supporter
May 25, 2006
7,549
Ft. Lauderdale
Good morning.
I mounted HRE wheels on my car.
The tires are Michelin Supersport Pilot, 245 x 35 x 19 at the front, and 345 x 30 x 20 at the rear.
Not only is there no problem, but most of all, my Ford GT has become MUCH MORE NICE TO DRIVE.
(The decoration on the tires is not original. I did it).

View attachment 45760

How did you apply the white letters?

You call those tire letters ?!?! :biggrin tirestickers.com here in the USA will make whatever you want..
 

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2112

Blue/white 06'
Mark II Lifetime
Do they stay on Long?
 

STORMCAT

GT
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Le Mans 2010 Supporter
May 25, 2006
7,549
Ft. Lauderdale
They have two options,, check out their website for both options,, full explanation of expected life, apllication etc,,
 

2112

Blue/white 06'
Mark II Lifetime
They have two options,, check out their website for both options,, full explanation of expected life, apllication etc,,

I saw the lifetime version. I was wondering if your experience was they lasted the life of the tire.
 

2112

Blue/white 06'
Mark II Lifetime
Saint Ho. Just noticed your gas cap.

I guess that addresses that issue! :biggrin
 

STORMCAT

GT
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May 25, 2006
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Ft. Lauderdale
I saw the lifetime version. I was wondering if your experience was they lasted the life of the tire.

The product is a thick rubber and is durable as described by the company. As far as staying on the tires it's all about the prep. They make it look easy but to do it right it takes a long tine to get the tires clean.. I did mine off the car. My letters are extremely large so lay out and install took a long time. I told my self,, never again but I wore out the Hoosiers with the white letters so I did it again , went yellow on some Bridgestones..
 

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