For temporary use, yes you can. But not on the drive axle. If its front wheel drive, you can use it on the back. Those tiny spares that come with the car are much smaller than regular tires. If you have a front wheel drive car that has a flat on the front, you are supposed to take a back tire off and put it on the front so the smaller spare goes on the back. You see it done wrong often.
Nope, don't do that. You might think 1-2" difference is negligible, but if you do actually have to use the spare in the future, it might shift the car's balance, and affect your steering capability. Like a table with 1 shorter leg.
Very annoying, risky and bad for your car's axle.
It's obviously not illegal to carry an odd sized spare as you don't have to carry one at all. It would be illegal to use it though.
The thing I'm not sure about is whether any type of wheel/tyre (but still of the correct circumference) could be designated a "spacesaver". If it could, then you can legally use it as a temporary measure.
You can use a narrower type but not a smaller diameter
If my car has 17" wheels can I use a 15" or 16" for a spare wheel. Is there anything wrong
