Made a BIG Mistake on my Rim Size

[Donny B]

:-? :-? Sorry for posting that last thread. I though I was ordering 17X9 rims not 17X8. My wife was looking over my shoulder when I was looking at the updates to my last thread. Since she is the one who does all of our finances. She had the invoice to my rims. She then told me that I didn't order the 17X9's. I ordered the 17X8's. :oops: :oops: I was quit upset for a little bit. But once i calmed down. It was than, I felt so stupid for the last post I summited. I know I'm an idiut. So, back to my question. What would be the best size tire for my 17X8 rims? I'm sorry again guys for the mess up.

[stangin99]

255 45 17?

i think thats the right size.

[BlueDonkey]

I thought it was 245 45 17; leastways that's what I got.

[Danger Dude]

All Mustangs with 17X8 rims come with 245 45 17 from the factory

[Dom]

well you'll get less road noise now. :|

[01mineralgrey6]

:yes:

[Dom]

But on the brighter side.

[Rick0636]

245/45/17 is the largest RECOMMENDED size, I have 275/40s on the rear of my GT, this is however stretching things quite a bit, 255/45s or 40s would probably be better, with the 275s on 8" I have noticed the outter tread does tend to turn up some, therefore you don't get full advantage of the 11 inches of tread with the 8" rims, they would be much better on at least 9" rims. I plan to get 9" or maybe 10.5 inch wide rims for the rear later on.

[Ponycarman]

Ideally, the tire width should be within 1" of the rim width, so a 7 to 9" wide tire would work best on an 8" rim. Too wide and the center bows out and wears first. Too narrow and the edges wear first, if you can get the tire to seat even. Low profile tires are harder to seat and too narrow makes it worse.

Steve

[Rick0636]

245s are 9", 275s are actually 11" so according to your formula they would even be too wide for a 9" rim, but that is what comes stock from Ford on the 03 Cobra on 9" rims.

[tire]

sorry rick not meaning to correct, just add...
245mm->24.5cm/2.54=9.65" and 275's are 10.8".

[Ponycarman]

Well, with all due respect to Ford's suspension engineers, I haven't been too impressed with the live axle setup on the non-IRS Mustang's. Or the front suspension either. Too many problems that could have been resolved easily and cheaply at the design stage rather than making those of us that like a handling car spend many dollars correcting them via the aftermarket or DIY fabricating.

Steve

[mikael]

7-9" TREADWIDTH for an 8" wheel, not section width. Tires are listed in
section widths. a 245/45/17 kumho 712 has a tread width of 9.1", not 9.65".
245/45/17s for 17x8s, 275s for 17x9s. any wider is a waste of money.

Those 245/45/17 kumhos ask for a 7.5-9" wide wheel to fit on. Each manufacturer
is a little different.

[mikael]

Quote: Originally Posted by Ponycarman Well, with all due respect to Ford's suspension engineers, I haven't been too impressed with the live axle setup on the non-IRS Mustang's. Or the front suspension either. Too many problems that could have been resolved easily and cheaply at the design stage rather than making those of us that like a handling car spend many dollars correcting them via the aftermarket or DIY fabricating. Steve

You're driving on a 1978 fairmont platform. What do you expect? It's
a tried and true, easy to produce setup. They're finally changing it with the
05.

[Zim]

ive had both 255 and 245/45/17 inch tires on my 17x8s. I dont really notice any difference

[Rick0636]

Thats because its only one tire size difference, its not a lot of difference, try squeezing some 275s on there, you will notice, its really a bit too much tire on the 8" rim, it will go on there, but it is going to bow some, mine actually seem to bow near the outside of the tread. I have pictures, but its hard to see it in the pics.

[Rick0636]

here it is.... these were made this afternoon...

[Rick0636]

I know I had one from the rear, if I can find it....

[Rick0636]

OK, look pretty good? Wanta take a peek under the hood? Ok sure....

[Zim]

my brother put 245s on his 7.5" rims they look kinda funny

[Rick0636]

This is one thats closer up right after I got them mounted, you might be able to see more what I am talking about. See there on the outside edge of the tire about like two inches from the edge on out its bowed, see what I mean? That is from the 8" rims.