Do you need to replace all 4 tires at once if only one or two are bad?

Here is a story shared in forum: I have an AWD Nissan Murano and got a flat tire that cannot be repaired. I called a Repair Shop and they told me because it was AWD I had to replace all 4 at the same time even though 3 tires are perfectly fine and only have 17,000 miles on them. Is he correct?

The answer to this question really depends on your car.

1.For front-wheel-drive or rear-wheel drive cars like BMW 3 series or Toyota crown , these don't necessarily need to have all four tires replaced at once. Usually two at a time is sufficient.

2.But all-wheel-drive systems are becoming more popular, and they do require all four tires to be replaced at one time. So for AWD vehicles,like Honda CR-V ,the short answer is yes.

For his case,we suggest him replace all tires at once .

Why two-wheel-drive cars need to replace two tires at a time but for AWD vehicles need to replace all four tires ?

On a front- or rear-wheel-drive vehicle, if half or more of the tread on all four tires is gone, replacing just one tire will result in one wheel spinning at a slower rate than the others, possibly sending false signals to the traction control and antilock braking systems. It also will result in one tire having more or less reaction for acceleration, braking and cornering grip than the others, which can affect a vehicle's behavior. On a two-wheel-drive vehicle, a better approach would be to replace both tires on the same axle. The best approach, though, is to replace all four if the tread on the old tires is significantly worn.

In vehicles with all-wheel-drive systems, including Subarus, Audis and Lamborghinis, the differential and the computer work together to send the right amount of torque to each wheel to minimize slippage and maximize control. If one of the tires is a different size than the others -- because three tires are worn and one is brand new -- the computer will take an incorrect reading and the differential will work too hard. Drive this way long enough and you'll burn out the drivetrain. All in all,on an all-wheel-drive vehicle or one with a conventional four-wheel-drive system, all four tires would ideally be replaced at the same time so they all have the same amount of traction as well as the same diameter.

Hence,before buy new tires ,it's necessary to check whether your car is two-wheel-drive or AWD vehicles.We just offer a few ideas and you could take as reference.If you decide to replace only one tire, it should be the same model, size and tread pattern as the others. A different brand or model tire will have even greater differences in traction and number of revolutions per mile, and it's likely to wear at a different rate. That means it could conceivably wear out faster than the others, even if it starts out with more tread depth.

Whether you decide to replace just one tire or more, tire experts advise that the new rubber should be mounted on the rear. If new tires are mounted on the front, the worn tires in the rear would be more susceptible to hydroplaning —riding on top of water on the road and possibly causing the vehicle to spin in a turn.

We are dedicated to providing reviews, tutorials, and much more on cars,ATV and motorbike. If you like it and want to see more,you could keep an eye on our blog as we have lots of blogs about automotive on the way.