85 RS Wheels

[Messe]

I have looked through the forums to no avail, so I need to ask.
My RS is all original daily driver, and I was wanting to know what is the largest wheel & tire I can run without any mods?

Thanks

[wraithracing]

That is a loaded question that can be difficult to give a definitive answer to. Every car is different, especially with 40 years of wear/tear/repairs/etc.

Generally a tire that matches or is similar in overall diameter to your original 225/60/15 is the first thing to start with. So you are looking at @ 25.7" tall in most cases.

Next the stock wheel was 7" wide and in most cases you can easily go to 8" wheels with no issues. 9" wheels up front can cause issues, but clear in the back with no problems with the right offset. If you want the ability to rotate and lengthen your overall tire life, then running the same wheels/tires at all four corners would be the best option.

Most likely you are looking at an 8" wide wheel with @ 18mm-20mm offset. Although you will most likely need an 1/8" spacer on the front spindles to provide enough clearance for the strut.

Then you can choose your overall diameter based upon your preference or tire choice.

245/50/16
245/45/17
245/40/18

There are options to run an 8.5" wheel such as the 1993 Cobra Replica wheels. The same tire size can fit, but you could also run a 255/40/17. Hope that gives you some ideas. Keep in mind that many of the exposed lug nut with small center cap wheels can have fitment issues of the small center cap with the longer snout/dust shield of the 79-93 Fox spindle. This is especially true for wheels originally designed for the SN95 such as Bullitt, Cobra R, 2000 Cobra R, etc.

[Messe]

Thanks. I wasnt trying to be loaded, there are so many wheel/ tire combos thrown around with offset and spacers ect... and I know the overall Dia. has to close to the same or the speedo wont be correct. I was wondering I say i get some 17" pony rims yhat there wont be an inherent issue due to the size.

[5pointoh]

That was an excellent summary from Trey! I just bought another set of wheels/tires and have been researching it as well.

If your wheel and brake setup is all original you will have no problems finding wheels/tires. My situation was tricky because I have a 4 wheel disc brake set up from an SVO which complicated things.

Going to back to your question, yes 17 inch Pony rims will fit no problem. LMR has a great selection of them for 4 lug Capris like yours. For the fronts I would not go with 9 inch wide rims as they will likely rub either on the lower control arm and/or inner bumper cover. If you stick with a 17 x 8 you should clear everything easily. A 245/45/17 will be good. If you want to be really safe you can run a 235/45/17 which I did on my 85 GT.

For the rear you can stick with the same tire size if you want to go with a square set up. But if you are like me and like the more aggressive staggered look you could consider going up to a 10 inch wide wheel in the back and run a 275/40/17 tire. This may require some minor modifications or it may just fit fine right out of the box. Go to LMR.com and you will find a great selection of wheels/tires and tips. I recently bought my 10th Anny wheels/Nitto tires there. I have got a 9 inch wide rim in the front and it does rub slightly but I had no choice as that was the smallest width for a 5 lug application.

[wraithracing]

Thanks. I wasnt trying to be loaded, there are so many wheel/ tire combos thrown around with offset and spacers ect... and I know the overall Dia. has to close to the same or the speedo wont be correct. I was wondering I say i get some 17" pony rims yhat there wont be an inherent issue due to the size.

I understand. I just wanted to be clear about my response. Unfortunately so many ask the same basic question, but want to run 10" wide wheels out back or are looking at running 20" wheels. The Fox is somewhat limited on wheel and tire options, especially when sticking with 4 lug. The options are much better now than it was 10 or 15 years ago, but still limited. If you aren't trying to go crazy than 8" wheels on all 4 corners work very well. The 245/45/17 is a popular tire that is available in several brands, styles, etc. and are used by OEM on several vehicles so that helps keep the prices lower. If your RS is lowered than you may want to consider a slightly shorter tire, but that will affect your speedometer reading and generally require a new speedo cable gear and thus modifications. Good Luck!

[4-barrel Mike]

Speedometer gear swap is easy: https://lmr.com/products/Mustang-Spe...ear-Calculator

Mike