Can You Replace Just One Tire on an AWD Vehicle?

AWD Tire Tread Depth Requirements

Quick Summary
If you own an all-wheel-drive (AWD) vehicle and damage one tire, you may have to replace all four tires—even if the other three look fine. That’s because AWD systems are extremely sensitive to differences in tire circumference and tread depth. Installing one new tire alongside three worn tires can force the center differential, transfer case, or AWD coupling to work constantly, leading to overheating and potentially thousands of dollars in drivetrain damage. In this guide, I’ll explain why AWD tire replacement matters, when you can replace just one tire, and how to avoid costly AWD repairs.

SUBARU: So if you damage a tire and the 3 remaining tires are worn by more than 2/32″ compared to the new tire, you must replace all 4 tires on an AWD Subaru.

Audi: “The rolling radius of all four tires must remain the same,” or within 2/32″ or 4/32-inch (1/8″), depending on the model. Of course, that assumes all four tires are the same brand and model. If you’ve mixed brands/models, you must rely on circumference, which is a maximum difference of 1/2″. Again, the circumference MUST be measured with no air in the tire OR the vehicle suspended and all tires at the exact same tire pressure.

Porsche Cayenne states that the tread depth must be within 30% of the other tire on the same axle’s remaining treadwear.

Ford AWD (Explorer, Escape, Edge)~2/32″
Toyota/Lexus AWD2/32″ – 4/32″ depending on mode
Honda/Acura SH-AWD2/32″ – 3/32″
Jeep 4WDMore tolerant in 2WD mode; 2/32″ in AWD mode
Dodge/Ram AWDTypically 4/32″ max

This is a general guide, Always refer to your owner’s manual for the tire specifications for your vehicle

Do You Have to Replace All Four Tires on an AWD Vehicle?

One of the most common questions I get from AWD vehicle owners is: “I got a flat tire. Do I really have to replace all four tires?” Unfortunately, the answer is often yes.

When people hear that they need four new tires because of one damaged tire, they usually think the tire shop is trying to sell them something they don’t need. In reality, the recommendation is based on how all-wheel-drive systems work.

I’ve seen customers save a few hundred dollars by replacing only one tire, only to end up spending several thousand dollars replacing a transfer case, center differential, or AWD coupling a few months later. That’s a very expensive lesson.

Why AWD Vehicles Are Different

On a two-wheel-drive vehicle, replacing a single tire is usually not a big deal. An AWD vehicle is different because all four wheels are mechanically linked through a series of differentials and drivetrain components. These components are designed to compensate for temporary differences in wheel speed during turns. They’re not designed to compensate for tire size differences every second the vehicle is moving.

The center differential exists because the front and rear tires naturally rotate at different speeds while turning. However, differences in tire circumference force the differential to compensate continuously rather than only during turns.

How One New Tire Creates a Problem

Here’s what many drivers don’t realize: A new tire is physically larger than a worn tire. Even if all four tires have the exact same size printed on the sidewalls, tread wear changes each tire’s overall diameter.

For example:

New tire tread depth: 10/32″
Existing tire tread depth: 6/32″
Difference: 4/32″

That may not sound like much.

But over thousands of wheel revolutions per mile, the new tire travels farther with each revolution than the worn tires.

As a result:

• The new tire rotates fewer times per mile
• The worn tires rotate more times per mile
• The AWD system constantly compensates for the mismatch

The uploaded article provides an example in which a new tire rotates approximately 835 times per mile, while a worn tire rotates about 839 times per mile. Those seemingly small differences add up quickly and can damage AWD components over time.

What Damage Can Occur If You Replace Only One Tire?

This is where things get expensive. When the AWD system continuously compensates for differences in tire circumference, it generates excess heat and wear.

Potential damage includes:

Center Differential Failure — Repair costs often range from $1,500 to $4,000. The center differential is often the first component to suffer.

Symptoms include:

• Binding during turns
• Shuddering
• Drivetrain vibration
• AWD warning lights

Transfer Case Damage — Repair costs can exceed $3,000.Many AWD systems use a transfer case to distribute power between front and rear axles. Excessive differential action can overheat gears, bearings, and clutch packs.

AWD Coupling Failure — Many modern AWD vehicles use electronically controlled clutch packs. Constant slip overheats these components and shortens their lifespan.

Premature Bearing Wear — Unequal tire diameters create drivetrain stress that can accelerate wear on:

• Differential bearings
• Output shaft bearings
• Axle bearings

Which AWD Vehicles Are Most Sensitive?

Some manufacturers have tighter tire tolerances than others. Subaru is famous for having some of the strictest AWD tire requirements.

Other manufacturers, including Audi, Porsche, Nissan, and many luxury brands, also have specific tire matching requirements. Always consult your owner’s manual for the exact specification.

When Can You Replace Just One Tire?

There are situations where replacing a single tire is acceptable. Generally, this is possible when:

• The remaining tires are nearly new
• Tread depth differences remain within manufacturer specifications
• The replacement tire is the exact same brand and model

For example, if your existing tires have only lost 1/32″ to 2/32″ of tread, a single replacement may be acceptable. Again, always verify the manufacturer’s limits.

The Tire Shaving Alternative — Many drivers don’t know about this option. Some tire suppliers can shave a brand-new tire to match the tread depth of the remaining tires.

This gives you:

• Matching tire circumference
• Proper AWD operation
• Lower replacement cost

Why Tire Rotation Is Critical on AWD Vehicles

One of the easiest ways to avoid this problem is to rotate tires regularly. I can’t emphasize this enough. Rotating tires at the intervals recommended by the manufacturer helps:

• Equalize tire wear
• Maintain a matching tire circumference
• Extend tire life
• Protect expensive AWD components

My Advice as a Technician

Whenever an AWD customer asks whether they can replace only one tire, I tell them to focus on the entire cost picture. Saving $200 to $500 on tires isn’t worth risking:

• A $2,500 transfer case
• A $3,000 center differential
• A $4,000 AWD repair

Before making a decision:

• Measure tread depth on all tires.
• Check the manufacturer’s specifications.
• Ask whether tire shaving is available.
• Compare tire replacement costs to drivetrain repair costs.

Most of the time, the correct choice becomes obvious.

Final Thoughts

AWD systems deliver outstanding traction and stability, but they also require additional tire maintenance. Because tire circumference directly affects how the AWD system operates, replacing only one tire can create constant drivetrain stress that eventually leads to costly repairs.

If one tire on your AWD vehicle is damaged beyond repair, don’t assume you can simply install a new tire and drive away. Measure the tread depth, consult your owner’s manual, and ensure all four tires remain within the manufacturer’s specifications. Spending a little more on tires today can save you thousands in drivetrain repairs tomorrow.

© 2012 Rick Muscoplat