Nuke

Try this: http://www.discounttire.com/dtcs/infoTireMath.dos

If you go with a taller (larger O.D.) tire with no additional power to back it up, the car will become a dog. Try to stay with the OE diameter. Even a 1" taller tire only reduces the gap by 1/2" but will also raise the car 1/2".

jdmcbride

The biggest tire I could find on tirerack.com without going to a truck/SUV tire is 275/45/18. This would be 10.8" wide tire and have a diameter of 27.8". This size tire would be the max I would go on an 18 x 8.5" factory wheel.

HTH

crazyhorse

jdmcbride
Thanks.
Do you know or have you saw 275/45/18's being run on a 07 mustang or equivalent?
Those would probably look good.
This sound more like something i'm interested in.
Is a 275/55or50/18 available?
Thanks again.

jdmcbride

I have not seen a 275/45/18s mounted on a Mustang. I have seen tires that were the same diameter as them though - they were 275/35/20s. They do fill the wheel well up better and look good in that aspect, but I don't prefer 20" wheels.

Once you get to 275/50/18s and taller, you can only get SUV/truck tires. This would not work well with a Mustang as they are designed for a much heavier vehicle.

Nuke

I'm running 275/40/18's all around and I'll run 255/45/18 front and 285/40/18 rear when I have to change rubber. Those 275's tramline terribly on worn, rutted roads.

crazyhorse

Thanks to all above.


I am in need of tires, so thought I would ask again to make sure since the tire shop where I will be getting the tires from will order them and will need the tire size to order. I will be stuck with the size I have him to order, so I want to be sure.
.
So here is the question " What is the biggest 18" tire I can run on a 07 mustang gt with stock 18" wheels "? By biggest, I mean just that, both width and height. I would like the size stated if possible, such as 275x45x18.

Not been lowered.

Thanks in advance for the information.

crazyhorse

Any numbers ?

mayo

100% correct.
If it was me on the stocker wheels, I would go with the 255/45/18 up front and 275/45/18 on the backs. I would stay away from the 275's up front as it visually is not needed.

Nuke

That would depend on the width of that 18" wheel, which you can find by looking on the inner face of the wheel (from under the car). It should be stamped. My stock 18's on my '07 were 8.5" wide and my '07 GT500 takeoffs are 18" and 9.5" wide.

Once you know the wheel width, you can find the widest tire that you can put on it from the tire specs (i use tirerack's spec info). Also, any of the online tire calculators will let you compare the OE tire size to whatever you're considering and will show you the tire O.D. difference and speedometer error (unless you select a tire that has an equivalent O.D. which is usually preferred).

157dB

I have 275/45-18s on my 18x8.5" stockers and they fit and perform fine.

275/40-18 BFG KDWIIs.

Thats the widest I would recommend on an 8.5" wide rim.

www.tirerack.com

Before those I ran 255/45-18s KDWIIs and wore them straight across
before replacing them. Proper tire rotation is the key to good tire wear.

235/50R18 STOCK
9.251" WIDE
27.251" TALL
85.641" ROUND
740 REVS / MILE

245/50R18
9.645" WIDE
27.645" TALL
86.851" ROUND
729 REVS / MILE

255/50R18
10.039" WIDE
28.039" TALL
88.088" ROUND
719 REVS / MILE

265/50R18
10.433" WIDE
28.433" TALL
89.325" ROUND
709 REVS / MILE

245/45R18
9.645" WIDE
26.681" TALL
83.821" ROUND
755 REVS / MILE

255/45R18
10.039" WIDE
27.035" TALL
84.934" ROUND
746 REVS / MILE

265/45R18
10.433" WIDE
27.389" TALL
86.047" ROUND
736 REVS / MILE

255/40R18
10.039" WIDE
26.031" TALL
81.780" ROUND
774 REVS / MILE

265/40R18
10.433" WIDE
26.346" TALL
82.769" ROUND
765 REVS / MILE

275/40R18
10.826" WIDE
26.661" TALL
83.759" ROUND
756 REVS / MILE