First time Mustang owner here, and love every inch of my GT. Just realized there is no spare tire. What to do when/if you get a flat? Anyone know?

 

Cry for help?

 

You can buy the spare tire kit from Ford. However, if you have staggered tires on your GT, the spare will be smaller then the rear tires, and that may present a problem with the differential. Someone with more knowledge hopefully will chime in and correct me if I am wrong.

The only alternative, if it is a side wall puncture, is to call for a tow and then buy a new tire.

 

Ford gives you road side assistance, but try using that on a Sunday...

Either buy the spare tire kit from Ford as SD CALSPCL says, or find a rim and tire size that will matchup with yours. There are a few threads on here for the S197's that might help.

 

The Ford Road Side Assistance uses the same people that provide it for AAA. Won't be any different than calling AAA on a Sunday.

 

I can summarize, I went through this with my 2014 GT.

1. The problem specifically was cars with Brembo brakes, the standard GT spare won't fit over the Brembos, and a bigger spare wouldn't fit the space in the trunk.

2. There are wheels that clear the Brembos and fit the trunk OK. They may stick up a bit. Not sure what would happen on the S550.

3. My solution was to obtain the 18" aluminum spare from the non-Brembo GT as well as the jack and tools. I then purchased a Slime Smart Spair compact inflation kit and a plug kit so I have options on a long road trip. There is a risk of differential damage (supposedly) using the compact spare on the rear as the spare tire diameter is approximately 3/4" smaller than the Brembo tire. So that's a last resort. It may be possible to use a high quality wheel spacer to install the spare tire over the Brembos (more like beside them) but this was never confirmed. If you have 4 Brembo brakes I'm not sure this will work at all.