VSThe Vehicle Standard
Menu
Questions/AWD and 4WD

Direct automotive answer

Can AWD tires be replaced one at a time?

Sometimes, but circumference differences can affect certain AWD systems. Follow the manufacturer’s tread-depth and matching requirements. This awd and 4wd answer depends on Tread-depth difference, Tire size, Manufacturer limit, Driveline design. Confirm each against the exact vehicle rather than assuming a class-average figure. The sections below break this down further: what the manual usually specifies, if one tire is damaged, why rolling circumference matters. 4 related follow-up questions are answered separately below, each with its own conditions attached. This site reviews every answer under a configuration-first standard, verified against NHTSA tire and vehicle guidance and linked to related awd and 4wd questions for the adjacent decisions this one usually raises. It sits within a awd and 4wd library of 8 related questions, held to the same configuration-first standard.

Often not without conditions. A single new tire has a larger rolling radius than worn ones, and many all-wheel-drive systems interpret the resulting speed difference as continuous slip, which can cause heat and wear in the coupling or differential.

Manufacturers commonly state a maximum permitted tread-depth difference across the vehicle, and some require replacing in sets or shaving a replacement tire to match.

What the manual usually specifies

Requirements vary by system, so the owner's manual is the controlling document.

  • A maximum tread-depth difference between tires, often small
  • A requirement to replace in axle pairs or full sets
  • Matching size, model and sometimes construction
  • Guidance on shaving a new tire to match existing tread depth

If one tire is damaged

Where tread depth on the remaining tires is still close to new, a single replacement is often acceptable within the stated tolerance.

Where the others are well worn, replacing in a set, or shaving the new tire, protects the drivetrain and keeps handling balanced.

  • Measure remaining tread on all four before deciding
  • Compare that spread against the manual's stated tolerance
  • Ask the tire retailer about shaving if a set is not practical
  • Check whether road-hazard coverage on the original tires applies

Why rolling circumference matters

An all-wheel-drive system's centre differential or coupling is designed to absorb the small speed differences that occur in normal driving. A new tire on one axle and a half-worn tire on the other creates a permanent speed difference the system must absorb continuously.

Manufacturers state a maximum permitted tread-depth difference, and it is often small. Exceeding it heats and wears the centre coupling and can eventually require a driveline repair costing far more than a set of tires.

  • A few percent circumference difference loads the coupling continuously
  • Manufacturers publish a maximum permitted tread-depth difference
  • Continuous loading heats and wears the centre coupling
  • The tolerance varies by system: check the owner's manual

What changes the answer

  • Tread-depth difference
  • Tire size
  • Manufacturer limit
  • Driveline design
Methodology: how to verify an answer on one vehicle →Search EPA configurations →Decode the VIN →Check recall campaigns →

Common follow-up questions

What happens if I ignore the tolerance?

The system can experience continuous differential action, generating heat and accelerating wear in the coupling or differential, and handling becomes less predictable.

Does this apply to front-wheel-drive cars?

The drivetrain risk does not, but the handling balance argument still favours replacing in axle pairs at minimum.

Is tire shaving safe?

It is an established practice for matching a new tire to partly worn ones, performed by tire specialists. Confirm the retailer offers it and that the resulting depth meets the manual's tolerance.

What are my options if one AWD tire is damaged?

If the others are nearly new, a single replacement may fall inside the manufacturer's tread-depth tolerance. Otherwise a tire shop can shave a new tire to match, which is cheaper than four; outside that, replace all four.

Related questions

AWD and 4WD questions and answers: the complete category

What is part-time 4WD?→What does 4WD low do?→Does AWD reduce fuel economy?→What is the difference between AWD and 4WD?→

Evidence

Why the tread-depth gap matters

On an all-wheel-drive vehicle the front and rear axles are linked, so a tire with a different rolling diameter makes the drivetrain work against itself. A new tire has about 10/32 inch of tread or more, a worn one far less, and that difference changes the tire's circumference. The center differential, transfer case or coupling is forced to slip constantly to make up for it, which produces heat and wear that can end in an expensive repair.

The published limit is small. Tire Rack advises keeping all four tires within about 2/32 inch of tread depth, or a quarter inch of circumference, of each other. Subaru specifies that if one tire is damaged and the other three are worn by more than 2/32 inch compared with the new one, all four tires must be replaced. Your owner's manual sets the actual allowance for your vehicle.

If the other three tires are nearly new, a shop can shave the replacement down to match them, cutting away as little rubber as possible. If they are half worn, the practical answer is a set of four, or a pair only where the manual allows it and the pair goes on the same axle. Rotating on schedule keeps the gaps from growing in the first place.

Sources: Tire Rack: Can tires be shaved to match tread depths on AWD and 4WD vehicles?; Tire Rack: Do all 4 tires need to match on an AWD vehicle?