Car Parts Faqs

When replacing tires on an car with AWD drive do you need to replace all 4 at once, or can you do 2 at a time?

A tire dealer said all 4 need to be replaced at the same time on AWD vehicles.

Public Comments

1. If you really had to replace all 4 tires at the same time on all wheel drive vehicles, the manufacturer would not sell many of these autos, NO, you don't need to, BUT you really want to stay with the same size tires.
2. You can get by with just buying two at a time (put them on the same axle) if you use the same size tires. The drive mechanisms will adjust for small differences front to rear. But they do not compensate as well side to side.
3. You can do two at a time. Just make sure you do it on one axle and that the differences between the axles isn't huge, especially going into winter.
4. Tire Wear Limit is 2/32 Tread Remaining "But That's a Bear Minim!" Two is OK as Long as the Tread on the Two Rear is still Good "I'd use 5/32 as a Minim!!
5. it would be good if you did all of tehm at the same time especially if it is an AWD car
6. Its best to do all 4 but if you have two in good shape just put the used tires on the front and the two new on the back.
7. If you don't replace all four tires then you run a serious risk of damaging your vehicles transfer case or other expensive driveline parts. Last year one of my sister stores on the other side of town caved to a customers request that they replace only the one bad tire even though the vehicle in question was AWD and the guys at the shop knew better and told the customer as much. They guy wanted what he wanted (customer is always right) and they gave in. Within 45 minutes the vehicle came back on a hook with a blown transfer case and the owner sued the shop for damages - case still pending. There have been dozens of other lawsuits around the country for similar circumstances. At my shop if there is less than 20% wear on the tires we will replace only 1 or 2 on most AWD vehicles but only with identical matching tires. More than 20% and we will only replace as complete sets of 4 on most makes/models or let the customer drive off to some other shop without ethics. I'd rather lose the business than take the chance. Of course, you should always consult the vehicle manufacturer to be certain. Not all have the same recommendations. This is Subaru's for example: "For safe vehicle operation, SUBARU recommends replacing all four tires at the same time. WARNING: All four tires must be the same in terms of manufacturer, brand (tread pattern), construction, degree of wear, speed symbol, load index and size. Mixing tires of different types, sizes or degrees of wear can result in damage to the vehicle's power train." http://www.subaru.com/owners/carcaretips/index.jsp?pageid=tire&navid=TIRED_TIRES
8. If they are so worried about them being different sizes (worn tread) put 1-2 pounds more air in the old ones. They will expand and make up for the 1/32" difference.
9. It is highly advised to replace all 4 at the same time to retain the same handling characteristics on all 4 wheels. Most dealers will not install only 2 unless they are replacing a defective set and the other 2 are at 90% tread or more, and the same model tire. You can always find a shop that will do what you want, but a tire specialist will not because it compromises your safety. There are some AWD vehicles, like some Subaru, Mercedes, and BMW, for example, that will take a single pair without problems. There are a lot more, actually most on the road today, that can't tolerate a size difference, even that created by different tread depths, and end up very quickly with $1,000 bills to repair the coupling systems between front and back axles.