If you have a 4 wheel drive vehicle, do you have to replace all tires at once?

Question

I have had several people to tell me that I have to replace all 4 tires at once on my 4 wheel drive vehicle. Is this true and why??

Answer 1

Yes, that is mostly correct.
If you don't replace all 4 tires at once, they will turn at different speeds, because of the very small difference in size.
The tires rotating at different speeds will eventually wear out the differential. (I was told the differential, but others say the transfer case- whatever. It's not good for your vehicle.)
If you never (or very rarely) switch the tranny into 4wd and just leave it in 2wd, it would be OK to only replace the tires as a pair. (One axle at a time.) But eventually you will probably need to use 4wd - although it wouldn't destroy your car if you only drive like that a small distance, I would recommend replacing all 4 at the same time.
It is also the same for all-wheel drive vehicles, except that for awd, you absolutely must keep them all the same.
If you had one tire that was destroyed, (bad flat, shred, bubble, etc.) but the rest are OK, go to a used tire dealer, and they will be able to match up your tires with a tire of the exact same tread depth and size.
(You could also do that for 2 tires if you have one pair of fairly new tires and don't want to spend the extra money, but it would be better to just do it right.)
So, if you can't replace all 4, either replace both tires on 1 axle with new ones and try to limit your 4wd driving, or match them with the same size and tread from a used tire store.

Answer 2

On AWD vehicles (and a search through your owners manual will confirm this) all tires have to be the same brand, model, size and within a very narrow margin the same tread depth. That means if you have more than just a little bit of wear, if one goes, they all go.

The reason is not because you will damage the differentials but because you will damage the Transfer Case, which is the heart of the AWD system. Mismatched tires cause the transfer case fluid to overheat which damages the unit - and it is very, very expensive to replace.

On 4WD vehicles the problems are lessened but the same situation exists any time you have 4WD engaged.


Let me tell a little story.

Last year one of my sister stores put 1 tire on a 4WD Dodge truck because the customer insisted on purchasing only 1 replacement tire - he refused to buy four. They put it on even though they knew better. About 45 minutes after the customer left he called the store to tell them his car was broken down - the transfer case overheated and crapped out. He is now suing the store and he will win. Even though the customer insisted, the store knew it was the wrong thing to do but put one tire on anyway.

Several times a year I will lose a tire sale because I refuse to replace only 1 or 2 tires on an AWD vehicle and the customer won't pony up for four. I'd rather lose the sale than get that phone call. Heck, about a year and a half ago we had a customer come in with a Jeep (hybrid 4WD/AWD system) who had driven it on the highway for about 50 miles on the doughnut spare. The transfer case was so hot when we got it up on the lift we couldn't go under the car. And that's with the spare that came with the vehicle!

If you have any concerns for your specific vehicle it is always best to go to the source - see your owners manual or call the dealer.

ASE Certified Service Writer with 5 years in the tire industry

Answer 3

Ideally, you would do all 4 at once. If you can't do that right now, then replace them in pairs. You did say 4WD and not AWD. With 4WD normally, only 1 axle is driving the car and you have to shift into 4wheel. With AWD, both axles will drive the car, although they will split the torque so either the front or rear axle will get the most power under normal conditions.
So if you really have AWD then replace all the tires at once, and as said in other answers rotate the tires with the oil change and they will wear evenly and you'll get a lot more wear out of the tires. Good luck

Answer 4

Four wheel drive vehicles need the same size of tires in all four corners. The reason being that the gears in the differential will wear unevenly if you have two different size tires on the same axle. Just like a two wheel drive vehicle that has rear wheel drive requires that both rear tires are the same size for the same reason.

Answer 5

it is very advisable to replace all four tires at once and then rotate them every other oil change so that they wear evenly. The reasons are that when in four wheel drive all four wheels are locked in and are being driven at the same rate of speed...if one tire has different tread style, different size, or even different tread depth ie:worn tires on some wheels, new tires on others the wheels will not roll
equivalently and can cause transfer case failures.

Answer 6

If you have positive traction or limited slip axles, the tires on that axle should be a matched set. As for as front / rear the tires need to be the same size, brand & type. Tires on the front axle with 20 k more or less miles than the rear axle won't hurt a thing. You are not supposed to use 4WD unless it's slippery anyway.

Answer 7

Only for All Wheel Drive. You shouldn't be in 4 wheel drive if you have good grip anyway, so tire size isn't as important.

Answer 8

Just remember there is a difference between FOUR WHEEL DRIVE and ALL WHEEL DRIVE. In the former, switching only in pairs is OK, so long as you rarely use it in 4WD. in the latter, you need to replace all four at once.
I own both types.

Answer 9

You dont have to replace all 4 at once. People frequently replace their tires in pairs, and rotate them in pairs, front to back.

Answer 10

You can get away with 2, but it is better on the drivetrain if you do all 4