That spare kit will not fit cars with Brembo brakes.
He does not a PP car, so no Brembo’s
It's still the wrong diameter for the rear though, 25 and some odd inches whereas every factory wheel and tire combo measures around 27 inches. May cause issues with the non Torsen diff, I couldn't find out for sure.
so you are saying that would not work in the rear? I had CS, but non pp1. it's 255/40R19 all around with that CS. the ford accessories and LMR website say it will fit
It's not that it doesnt fit, it fits everywhere without the brembo brakes. But supposedly with a limited slip diff (excluding Torsen on PP cars), too much of a diameter difference on the rear axle causes accelerated wear. Just what I have read. With the Torsen you can go like 20% difference and be fine.
so the one from automotive authority kit is better?
It is, but it's also way more expensive and doesn't let the trunk floor stay perfectly flat. I wouldn't worry about it too much, its a 7% difference in diameter. Just be warned that if you do have to put it on the rear to only drive it as far as you need to get to a tire shop. You could also just swap it to the front and put a good wheel on the back and be 100% fine. I'd honestly do research on your own about it, the Trak Lok is clutch based and I'm not sure the wheel speed difference that's required to cause the clutches to engage. Different diameter means different wheel speeds, but I'm not sure how 7% different diameter translates into wheel speed and how that relates to the clutch lock up. I just know that the idea disturbed me so I went with the explorer spare, but that doesn't clear the front brakes on ANY GT, which I didn't realize.
I would only put the spare to the front then.
This is the original Ford spare. There is absolutely no issue using it on any Mustang except those with the Brembo 6 pot fronts. It is for limited use and moderate speed. The small difference in diameter is no cause for concern. I had one on my 15’ EB with 18’ and my 19’ GT/CS with 19’s. No issues. Just do not try and do a Cannonball with it.
Mine lets the floor of the trunk fit flat. Took a bit of mild encouragement with the heel of my hand in a spot or two, but it did get in once I had it level.
You should be fine on either axle, assuming you keep to the notification on the tire (typically 50 miles / 50 mph).
