Need new tires – 3.5 years old and 32k miles. I have a full size spare, never used. Is it okay to buy 3 new tires of same make and model, use the spare as the 4th, and use the least worn current tire as new spare?
I would only consider doing this IF you can find the exact same tire and the tread design still matches the current “spare” tire. Since rubber compound could be different it isn’t a great idea but if money it real tight it can work, but you need to find 3 other tires that match. Since many shops give a special price on 4 tires, buying 3 might not save you any money.
If you have a full sized spare on a matching rim with the others, it should have been part of your tire rotation routine. If it is on a steel rim, where the others are on mag rims (like my spare), your better off leaving it there as your spare, and getting four new tires. The tire shop will still charge you for putting that tire on a mag rim and balancing it. They may even charge you for putting a worn tire back on the spare rim to maintain a full-sized spare. In the end, you’ll not save any money.
Yes, it is OK. I had been doing it this way for years, until the time when new cars only came with compact spares.
Essentially, you can do it only once. Your spare is now too worn to put back on the car so it becomes your permanent spare.
In making your decision this time, see if your tire store is offering a special 3-for-4 sale. In that case it may be better to buy a set of 4.
Only other thing to check is the actual age of the spare, look at the tire code (google ‘decoding tires’ to find out what it means). I could be older than you think.
As usual, The Devil is in the Details, and the vitally important detail that is missing here is actual information regarding the OP’s vehicle.
The responses that were given so far are helpful and are essentially valid, EXCEPT if the vehicle in question has AWD. If this is an AWD vehicle, saving some money by buying only 3 tires will pale by comparison with the cost of repairing the AWD mechanism.
Since the first or second response usually asks for information about the vehicle, I am really surprised that I am the first person to want to see details about the vehicle.