4WD vehicle - Can I replace just one tire, not all 4?

I got a flat on my Jeep Liberty the other day. My boyfriend put the spare on (which looks like a regular tire, not a “donut” like I was expecting), so I’ve been driving around on that temporarily. I was told that if the flat tire is not able to be patched, I should NOT keep the spare in its place. They also say that I’ll have to not only buy a NEW tire to replace the flat, but I’ll actually have to buy FOUR new ones, because that’s something special about 4WD vehicles: you have to have all 4 tires on the exact same amount of wear and tear… Is this really true, or is it just a scam that tire shops invented to try to make you spend more money? Ideally, I would simply like to buy ONE new tire, to take the place mf my spare that I’m currently driving on. Anyone have any expertise they can share?

How many miles on your other 3 tires?
If the spare has never been used before, then you might want to replace that as well, due to age(you didn’t specify the year of the vehicle).

Generally you need to have all four tyres with very close diameters. Different sizes wears the 4WD stuff and can result in some expensive repairs. Check the car’s owner’s manual for information about your specific car.

Note: you can have a larger tyre shaved down to match the other three. That may or may not be a good idea for your specific situation.

Check your owner?s manual, but you should be fine only replacing the one tire. The 4 matching tires are usually only required on full time all wheel drive vehicles like Subaru’s. If your Liberty can be shifted in and out of 4WD, then I wouldn’t be too worried. The four wheel drive is normally fully disengaged, and in the rare times it is selected a small tire size difference won’t make much of a difference.

As noted, the owner’s manual will tell you the answer and it can matter, but doesn’t always.

I’d just add in that since you are equipped with a full size spare, whenever you do get the tires replaced I’d go to a regular rotation schedule that includes the spare. This will not only tend to increase the mileage you get from your tires, but will always leave you with a spare that matches the other tires.