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Do I need to replace all 4 tires at once?

I have a fairly new Hyundai Sonata (V4 GLS) (purchased last may, 12,000 miles on it) and I recently got a flat tire (the tire itself doesn’t appear salvageable). If I purchase a new tire is it OK just to buy two, or do I need to replace all four tires? Thanks!

This is just front wheel drive, right? If so, there’s no mechanical reason why you need to-- it’s only all wheel drive vehicles that are overly sensitive to it. However, in terms of maintaining predictable handling it is a good idea to at least replace them in pairs if the rest of the tires have significant wear on them.

If you can buy one tire that’s exactly the same as the others, go for it. Check with or on eBay.

You don’t need four. Do you have a full size spare? If you do I would buy one new tyre, and put the new and the spare on the rear and use the remaining two good original tyres on the front.

Next best would be to use the two best on the back and the others on the front.

Yea, It sounds strange to put the best tyres on the back rather than on the front that carries more weight and puts all the power to work, but it is a safety issue. In an emergency handling situation, you want to tyres on the back to stay there, otherwise you end up looking where you were with the back end leading the way. They guys who look at accidents say the best on the back , and I would believe them. Hopefully neither you nor I will ever need to find out if that is right.

12k is typically not much wear. I would simply replace the tire with the exact tire model/size.

First, what flattened the tire? A nail or screw? Unless money means nothing to you, and the nail or screw is the only accessory to the tire, use a can of Fix-a-flat and drive the car until the tires wear out. Leave the accessory in situ. If a nail head clicks on the pavement, cut the head off, and leave the rest of he nail in the tire.

I would NOT use that under these circumstances. If the tire isn’t salvageable…then why take the risk. This is dangerous to the driver and everyone else on the road.

Fix-a-Flat is at best a poor substitute for a spare tyre. It will make a real mess inside and it is not considered a safe permanent fix. If you have a nail or screw damage, it MAY be repairable, or may not, depending on the location and nature of the damage. If it does not “appear” salvageable I certainly not want it on my car. I like living and on occasion I driver over 15 mph.

Buy one identical size replacement tire with the same traction rating as specified on the sidewall. Google UTQGS for more on this from NHTSA. If you can easily do it, get the same treadwear and temperature rating too but those may not be as important. Any nationally recognized brand will work OK.

Go further and buy the same tire if you drive on ice or snow. Tires have differing levels of traction in these conditions from excellent - really poor. Having a difference can throw off the equilibrium of a vehicle in really slippery conditions. If you live where this a rare event it is a non issue.

Like others have said, Fix-A-Flat is not a repair. It is a stop-gap measure to allow you to get to a place where you can get the tire properly patched or replaced…AND MANY VARIETIES OF FIX-A-FLAT ARE FLAMMABLE!!!

Leaving the nail in the tire is even more bone-headed! Even if the worst cheapskate hack would remove the nail and plug the tire himself!

There are a few reasons to have “identical” sized tires, especially on the front:

  • A taller tire on one size will pull the car to one side, even if the alignment is perfect (think about rolling a styrofoam coffee cup around on a table)
  • Having a diameter mismatch means that one axle is turning at a different speed than the other axle, some people think this will cause some sort of damage
  • Some new cars use an “indirect” TMPS (tire pressure monitoring system) that uses the ABS system to detect a slight difference in wheel speed, which leads the TMPS to conclude that one tire is underinflated relative to the other tires

However at the end of the day, if you put the new tire on the rear, there aren’t really any significant downsides. That’s what I would do if it was my car.

NOW, you are talking about something dangerous----those tire plugs! With a tire plug, you have made an 1/8th to 3/8th inch hole in the tire where before there was just a benign 1/8th screw or nail. Reaming the hole, and forcing in the plug, causes additional structural damage to the tire cords. When that plug blows out, and they do blow out, you have an instant, dangerous, flat!
“The tire is not salvageable”. I missed that. Many flats occur from screws and nails, and they have slowly leaked down over several days. Ideally, it would be best to patch the tire; but, there are many tire repair places which will lie and say, “We can’t patch tires. They have to be plugged”, or, “It is shop policy to plug tires, not to patch”. Also, there may be monetary constraints (ever had those?) for patching.
It doesn’t make fiscal sense, or otherwise, to replace an expensive (for some people) tire that cost from $50 to $300 because it has a benign, slow leaking, little nail or screw in it. Don’t forget that rubber is deformable and will flow around an inclusion (such as a nail or screw), and the tire reinforcing fibers have only been pushed aside by nail or screw-----a small, local distortion-- not like the brutal ripping hole you get from a tire plug insertion.
Products like Fix-a-flat are, now, non-flammable, by law. Also, by law, they are required to say that they provide only a temporary solution. I’ve run tires for years with Fix-a-flat like products stopping small slow leaks, and leaving the nail or screw in—because tire are, you know, rubbery. And, the inclusion (nail or screw) causes no structural harm.

Your owner’s manual may have the spec for allowable difference in tire diameter. The tires should all be the same nominal size - for example 205/65R15 - whatever the car is manufactured with and as labeled on id label on the driver’s door or post. Tires on each axle must be the same size and model. If tire wear is not significant, replace 1 one tire as above. If worn beyond Hyundai’s spec for single tire replacement, replace 2 and put them on the front. It is best to replace 4 at once, but with only 12,000 miles, it may not be necessary.