Are you talking about 18 and 24 inch tires(the rubber part only) or wheels(the metal piece that the tire is mounted to, commonly refered to as the "rim")? I will assume you are talking about wheel size. The main concern here is that the overall tire diameter is the same. As long as the diameters are the same, it wouldn't be a problem to TEMPORARILY use your stock spare. If they have different diameters, you SHOULD NOT use the 18"spare as it will cause a difference in the final drive ratio between two tires on the same axle which will, in turn, cause serious problems with your drivetrain. If you need help figuring out the diameter of your 24" vs 18" please post more info including tire size(tire size is molded into the sidewall of the tire and should read like this: P265/70-R17) and make and model of vehicle.
Not sure what you mean by regular tires, but a 17 inch tire will fit a 17 inch rim.Not sure what you mean by regular tires, but a 17 inch tire will fit a 17 inch rim.
no 15" tire will not bead up
No. You will not get the tire on the rim without tearing it.
No. Even if you were able to stretch the tire on the rim, it will cause damage to the tire.
If the tire is built for a 17 inch wheel, yes.
If you want to replace the current tires on your vehicle with a 17 inch tire you will have to have the proper rims for that tire. If you currently have rims for a 17 inch tire then you would not have to replace them but if your tire rims are smaller or larger then they would have to be replaced.
I have a 2002 Nissan altima with tires 205/65R16 can I replace them with 215/65R15, the tires came on 5 bolt rims and will fit on the altima. If the tires are on 15 inch rims, you are ok. You can not put 15 inch tires on 16 inch rims, or 16 inch tires on 15 inch rims.
No... The tire is to big and would not "bead" on the rim correctly.
NO ! -Tires must always go on the correct rim.
Put in properly it may last the life of the tire.
Rim size is important since you can't put a sixteen inch tire on an eighteen inch rim. But tire width is important too. Don't try to put wide tires on narrow rims. If you have questions, your local tire professional would be a good resource. Perhaps he/she would be impressed that you're a "chick".
For stock truck a 31 inch tire is the biggest possible and even this tire will rub