JasperGT

I am looking to change up my wheels a bit by getting some TSW Nurburgring wheels. They would be 18" wheels in Matte Gunmetal. The wheels must be all the same width (so I can rotate them) and they should be able to fit 255-275mm tires on all four corners.



Here is the problem: The TSW website says that their 18x8 w/ 35mm offset will fit a 2007 Mustang (which would not meet my tire size requirement), and their 18x9.5 w/ 40mm offset will fit the rear. I have also found online 18x8.5 w/ 45mm offset and 18x9 w/ 32mm offset wheels These wheel sizes do not come up on their fitment guide for the mustang, and I'm not sure why that is.

If I am to do this, I would be selling my CS40s. If I could do that, I am thinking I would get the 18x9 w/ 32mm offset with 255/45/18 tires or 18x9.5 w/ 40mm offset with 275/40/18 tires. Will these wheels fit? Is there a problem with running 9.5" wheels up front?

Also, here is a chart I made showing the different offsets and the calculated backspacing. Let me know what you guys think, and please let me know if there is something wrong with the calculator. I made the spreadsheet in Google Docs because I don't have Excel. Hopefully it'll open and work for you guys.

Here is a screen shot in case you can't open it:

JWButler14

what size and color are your cs40s? and how much do you want for em?

jawsgt

the roush wheels are 18x10 all the way around so im sure ull be fine. if you go with 18x9 i would run 275 tires but if u go with wider wheels ide look into 285 tires. i had 18x10 wheels with 275 tires and they were extremely stretched onto the wheel. u can easily get away with 275 tires on a 8.5 wheel also.

6+6 Stang

although i run staggered now with my new 20" 295 on rear 255 on front, down road was thinking going a little narrower and taller side wall could you put a 255 on a 10" rim, then would go taller 255 on my 8.5 up front, can you run same size tire just cuz one wheel wider or narrower?

KeneticEnergy

run the 18x9's with 255/40 all around if you are staying with that wheel. 18x9.5 et40 will sit way too far within the fenders, just like the stock wheels

dont go crazy with something like a 275 on a 8.5 either; yeah they'll fit on the wheels but it will be detrimental to your handling, wear the tire in odd ways, and won't make proper use of your tread.

6+6 Stang

guess sticking with what came on wheels 295/30/20 on 10" rear and 255/35/20 on 8.5 front.

Norm Peterson

Came here from the 10" wide +40 offset thread . . .Your spreadsheet opens just fine. I think the GT500 wheel has a slightly thicker flange, as the backspacing listed in the FRPP catalog is 7.12" IIRC.


It's the screen shot that I can't open (internet filtering at work).


There are a couple of people currently running 275/40's on the GT500 18x9.5 wheels on all four corners of the car. I think Nuke is one of them.

FWIW, a 275/40 on a 9.5" wide rim is not an awful lot wider (section width, across the sidewalls) than a 255/45 on the same width rim. The reason is because the 275 tire is measured on a 9.5" wide rim to begin with. The 255/45 is measured on an 8.5" wheel, so when you mount it on a 9.5 it gets wider by about 0.4" (10mm). IOW, the 255/45 ends up looking about what a 265/43 would start out looking like if anybody was to actually make such a size. Imagine midway between what a 255/45 and a 275/40 start out at.

Except for the width of the tread, which pretty much stays at its design dimension.

If you'll post your current tire size and wheel width and offset, I can put up comparative plots for you. 275/40-18 vs ???/??-18.

The range of widths for a 275/40 tire is from 9" to 11". You aren't really "stretched" until you put them on 11.5's. Most of the people who think 10 is a stretch for a 275/40 are the same ones who will pinch a wide tire down onto wheels that are half an inch or more below the tire mfrs' minimum width recommendation.


Norm

07GrabU

wow, giving up CS-40's for those? The CS-40 is one of the sexiest wheels out there. If those CS-40's you are unloading are the Machined with Black accents that's what I am looking for for my car.

2005Redfire6

Agree with others the current ones you have are sick but at the same time I love that style wheel you posted.

Blacksmoke

I am running 18x10's all the way around.
I have Nitto 555 275/40ZR/18 130W all the way around.

Two things you must be careful of for the fitment up front.

1. the offset (mine are 42 I believe)
2. Watch any wheel that is deep dish or the spokes move inward