[Rocket455]

Had a sudden and massive tire blowout on the freeway (driver front), luckily was able to limp to safety. Planning on purchasing the Modern Spare kit (link below). Rolling diameter of the donut is 26.5", my current set up is 27.7" (square), that's 4.3% / 1.2" difference in the diameters. Is it ok to drive under 30mph for a few miles with the donut, or will I really do a number on the differential?

https://modernspare.com/product/2017...e-kit-options/

[HerkHealer]

Originally Posted by Rocket455

Had a sudden and massive tire blowout on the freeway (driver front), luckily was able to limp to safety. Planning on purchasing the Modern Spare kit (link below). Rolling diameter of the donut is 26.5", my current set up is 27.7" (square), that's 4.3% / 1.2" difference in the diameters. Is it ok to drive under 30mph for a few miles with the donut, or will I really do a number on the differential?

https://modernspare.com/product/2017...e-kit-options/

I have the Modern Spare kit for my car. I have 20" 668 wheels and the kit I bought was exactly the same rolling size. Maybe you bought aftermarket wheels?

I would not recommend running a smaller tire, because i'm sure you realize it will spin faster than the other wheel/tire on the other side. And the diff will not like that at all.

Maybe talk to modern tire and see what they suggest? They may have a kit that will work for you. Get the kit that comes with the correct spacer and carrying bag. It fits perfectly in trunk using the tie downs.

[Rocket455]

Yes sir, aftermarket 19" wheels and running a slightly taller tire setup (245/45 instead of 245/40).

I suppose the safest bet would be to put the donut on there (as opposed to leaving the car propped up on the jack in the parking lot), take the blown tire/wheel directly to the shop without moving the car, and then swap it out again. Slightly more tedious, but better safe than sorry.

Originally Posted by HerkHealer

I have the Modern Spare kit for my car. I have 20" 668 wheels and the kit I bought was exactly the same rolling size. Maybe you bought aftermarket wheels?

I would not recommend running a smaller tire, because i'm sure you realize it will spin faster than the other wheel/tire on the other side. And the diff will not like that at all.

Maybe talk to modern tire and see what they suggest? They may have a kit that will work for you. Get the kit that comes with the correct spacer and carrying bag. It fits perfectly in trunk using the tie downs.

[HerkHealer]

Originally Posted by Rocket455

Yes sir, aftermarket 19" wheels and running a slightly taller tire setup (245/45 instead of 245/40).

I suppose the safest bet would be to put the donut on there (as opposed to leaving the car propped up on the jack in the parking lot), take the blown tire/wheel directly to the shop without moving the car, and then swap it out again. Slightly more tedious, but better safe than sorry.

I'd still give them a call and ask if they have a 27 or 27.5 inch setup.
A 27.5 spare would be fine in your situation.

[Rocket455]

Good advice. I ended up calling them just now and informed them of my situation. Their tech team said they don't have a taller setup, but the 26.5" would be fine for low speed / limited distance driving.

Originally Posted by HerkHealer

I'd still give them a call and ask if they have a 27 or 27.5 inch setup.
A 27.5 spare would be fine in your situation.

[Mike 540]

If you do not only need to drive accross the parking lot into a garage, I would say it could damage the diff - it was not built for that.