I did that just last year in my WJ, about 3 miles down a dirt road, and 15 miles from town. Well, I didn't slash it, I blew it out.

Murphy will get you!

Thanks

conclusion seems to be Yes you can ride with a different size mini spare wheel. But not in 4x4 and not for a long time, and not at high speed

the mini donut wheel must be inflated properly (60psi).

thanks

i'm gonna go against what everybody else is saying, and say no.

reason being, even a space saver in a 4wd/awd or even rear wheel drive is the same circumference as your stock wheels, only skinnier. (width doesn't matter)
if you do use it, your spider gears will be screaming. and if you've got LSD, you will burn out the clutches a mile down the road. don't take the chance. get a matching size spare.

Sounds ok to me...

But it seems the original donut wheel is smaller than the original stock wheels.

I’ll check.

Yeah, you definitely wouldn't want to use it on the same axle as an LSD or auto-locker. But with an open diff, I really don't see it putting too much stress on the spider gears, assuming you weren't pulling a heavy load up long hills for or running flat out at 100 mph for miles. I'm running 235/75-15 tires, and my mini spare is 125/90-16. That's an overall diameter of about 29" for the regular tire and 25" for the spare. That difference in diameter means the smaller wheel will rotate about 112 times more per mile. At 60 mph, you're looking at about 2x per second the spider gears would be turning. That doesn't seem like a lot to me, but it could certainly be a factor under higher load conditions.

Emergency. Use. Only. Not for long. Not at full speed.

Why is that so hard to understand?