Hi Guys, I was wondering if you could help me out. I recently ordered a new 2007 Mustang GT and it will be arriving in a few weeks. One of the first things I'm going to do is change out the factory wheels and replace them with a set of 19-inch or 20-inch wheels and a new set of Goodyears all the way around. I've been Googling the net for information on tire widths and general wheel specifications etc., but have been getting a lot of mixed information, so I decided to try here.*

What I'd like to know is when ordering a set of wheels, what is the preferred (or optimal) offset for the '07 Mustangs? I've heard somewhere between 30mm and 45mm, but was hoping for something a little more specific. And would that offset be "positive" or "negative" offset for these '07 cars?

The next question is (you guessed it).... What's the widest tires that I can squeeze under the rear fenders WITHOUT and suspension or fender mods. In other words, since I'm not looking to do any modifications to the fenders or the suspension (at this time), what's the widest tire that will fit the factory setup? I want to avoid ANY rub... I don't want the slightest rub or scraping at all. I've heard that people have been going all the way up to 315's in the rear with 20-inch wheels without any problems at all. I know that a seemingly factory/stock Shelby I looked at recently had 285's in the rear, and the one I saw at a local "cruise night" here in NJ had 305's in the rear and 275's in the front of his 2006 Shelby. Going with 285's, or even wider would be pretty sweet looking if it's possible. The "deep dish" style would definitely give the car a much more "aggressive" look. *

I checked out some wheels that Mustangtuning.com was offering just to get an idea, and I don't plan on going with that particular style, but the "deep lip" effect is something I'd like to achieve with my car. I just want to do it right and not make any stupid mistakes.* Same goes for the front tires...

*I'd like to go with the widest tires possible in the front as well. Again, the widest that will fit the stock factory setup (for now). This is where it gets a little tricky because I've heard that If you go with any width above 255's in the front the car will track and steer awkwardly. This would be unacceptable and probably dangerous! Of course, this could all be nothing to to worry about - we'll see. In any event, during my internet searches I read of people claiming to have put 275's on 20" wheels on the front of 2005+ Mustangs!*Thoughts? Suggestions?

It also might be worth mentioning that I eventually plan on lowering the car and adding all the appropriate suspension parts in the future. In the mean while I'm gathering as much information as I can. In particular, I'm searching for spot-on specifications for the optimal offset and maximum front and rear tire widths for both factory as well as for modified setups (i.e. a car that's been lowered). It would be interesting to know the differences and limits for both setups.*

I like the deep dish/low profile look. The specs. I jotted down from a stock 2006 Shelby I seen while at a local cruise night was as follows:

305/25/20's on the rear.*
275/30/20's on the front.

I'm also curious about how these tire and wheel combos will affect overall ride quality.

Thanks in advance for any information and suggestions you can provide!

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Ed

Hey Ed was just wondering if you put that much tire under that car what's gonna happen to your gear ratio? It will make it really tall geared and you will lose alot of your power.

Not necessarily... Depends on the side-wall height of the tire too. Low profile tires can bring the height more in-line with the overall height as it was shipped from the factory. One thing people can do is measure the overall height of the mounted tire/wheel combo from the ground up on a factory car and note what it is. Increasing the *wheel* size doesn't always translate into drastic overall height increases. As far as loss of power, yeah, I thought of that... However, larger tires may offer a touch more gas mileage. There is ALWAYS a tradeoff ;-)

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Ed

By the way the off set is negative. Hope you get your dilemma figured out. Have you priced out your tires yet?

I haven't priced out anything. Will wait until I get the specs. I need.

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Ed

How do you know the offset is negative? What's the range in millimeters?

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Ed

I just know that the off set is negative and to answer your other question, it will depend upon the wheel to know the range in millimeters.

Ed, I'm in the same dilemma boat as you as to the offset. I have been trying to verse myself for a couple of weeks. I have an 06 GT (bet you would not have guessed that), and also look for that "more aggressive stance" but I am staying with 18"at the max, likely Magnum 500's.

Far be it from me to disagree with RacerGirl since I know she is well versed in both vehicles and driving but it is somewhat confusing terminology. Here is what I have found:

Wheel Basics

So she would be right and you would need a negative offset to bring the rim out away from the vehicle and brake assembly. I am trying to find if anybody has used something such as this:

Wheel Adapter Spacer on Ebay

This extra 25mm (1") or even up to the max of 45mm (1.75") would allow both wider stance as well as more choices for any rim that had less than the 40mm offset that is normally required for an 05-07.

I, like you, am hoping to find somebody that has actually used these or done something similar to give feedback on how it works and any safety issues.

=Mach=

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=Mach=
'72 Mustang Mach 1 - Snow white with black stripe
'06 Mustang GT - Screaming Yellow

Go to any tire/wheel website (Discount tire etc..) they will tell you what fits your car.

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Hi guys, been a while since I checked back here to see if the discussion yielded any definitive answers. Anyway, I've been busy with other projects and responsibilities and haven't had much time to check the forums. I had the "largest wheels and tires" question posted on other forums - one was allformustangs.com. Still no definitive answer. Basically, I'm in search of the dimensions (i.e., overall width, back spacing etc.etc.) that are as accurate and as detailed as possible for the largest wheel/tire combo that will fit in both the rear and front of the 2005 to 2008 Mustang stock ride height and suspension. I'm still undecided on the wheel height as well since I've gotten mixed answers there too. Some claim 19s to be the best yet others claim that 20s would be perfect if matched to the right tires. I'm still not sure. There are a few dudes at a local cruise night that claim 20s are just fine, but I really don't know them too well. The cars look great but oddly they don't seem to be running the widest tires either. I think they both were only running 255s all the way around. I can't remember though. I've searched the web for definitive answers, but have yet to find anything. Have these questions been answered yet? There was a pretty detailed topic I had started here:

http://www.mustang.com/forum//showth...lnk&cd=2&gl=us

but it looks like the forums no longer exist

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Ed

ok i used to work for ford and i am telling you flat out the biggest rim is twenty's
if that isnt enough go to any ford show room the shelbys the saleens and anything above the base gt will have twentys on it from FORD. pick a rim and who you buy it from will tell you what tire will fit. also check out tirerack.com that site will also have all the answers. i personally recommend the wheel company Konig they make a wheel called "beyond". it looks sweet on any mustang

Just wondering if there has been anything definitive yet regarding the widest rim/wheel and tire combinations that will fit the 2005-2009 Mustangs. I took some rudimentary measurements and from the face of the hub where the back of the wheel meets the face of the rotor area i get 8 inches to the inside and 4 inches to the outside still leaving some wiggle-room. That would suggest an 11-inch rim with a 20-inch diameter (give or take).

The 285s that come on the Shelby's puts the overall width at roughly 11.25-inches. Supposedly you could go all the way up to 315s. I don't know how safe that would be but there seems to be about 13-inches of overall clearance in wheel well.

315mm works out to 12.4 inches leaving 0.6-inches or clearance or just over a quarter-inch to either side of the wheel tire combo.

305mm works out to 12-inches of overall width exactly and would seem to allow a half-inch clearance to either side.

Can anyone confirm?
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Ed

Have the dimensions be published somewhere yet?

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Ed