Can I Replace One Tire on My AWD?

Yes—but only if the new tire’s rolling circumference closely matches the other three, typically within about 2/32 inch (1.6 mm) of tread depth or roughly 0.3–0.5% in circumference. If the difference is larger, most automakers and tire experts advise replacing all four tires or shaving the new tire to match. This matters because AWD systems can be damaged by even small, continuous differences in wheel speed.

Why Tire Matching Matters on AWD

All-wheel-drive systems rely on closely matched wheel speeds to distribute torque smoothly. When one tire is taller or shorter than the others, it spins at a slightly different rate, forcing clutches, differentials, or transfer case components to slip constantly. Over time, that can overheat fluid, stress gears and clutch packs, trigger warning lights, and even void warranties if the mismatch is deemed the cause.

What Can Go Wrong With a Mismatched Tire

Even a few millimeters of diameter difference can make an AWD system “think” one wheel is slipping all the time. The result can be driveline binding in full-time systems, overheated on-demand couplers, nuisance stability-control interventions, and accelerated wear of center and rear differentials. EVs with dual motors can also suffer uneven load sharing and reduced efficiency.

When Replacing a Single Tire Is OK

A single replacement is generally acceptable when the other three tires are very close to new and the replacement tire is identical in brand, model, size, and service ratings. The most common thresholds are a maximum of 2/32 inch tread-depth difference across all four tires or roughly 0.3–0.5% difference in rolling circumference.

The following checklist will help you decide if a one-tire replacement is viable.

• Match exactly: Same brand, model, size, load index, and speed rating as the other three.
• Measure tread depth: If the remaining three are within about 1–2/32 inch of a new tire, a single replacement is typically fine.
• Check percentage difference: Aim for under ~0.5% circumference mismatch; many shops target closer to ~0.3%.
• Confirm with your manual: Some OEMs are stricter; a few require all four to match nearly precisely.
• Consider shaving: If your existing tires have more than ~2/32 inch wear, shaving the new tire to match can save the set.

If you meet these conditions, a single replacement won’t meaningfully increase drivetrain stress, and it should maintain predictable handling and stability-control behavior.

When You Should Replace Two or Four Tires

If the remaining tires are significantly worn, a single new tire will likely exceed acceptable tolerances. At that point, replacing in pairs or, more commonly for AWD, replacing all four is the safest choice.

These scenarios typically necessitate pairing or a full set.

• More than ~2/32 inch tread-depth gap between the new tire and the others.
• Rolling circumference mismatch above ~0.5% (often reached once the others are near mid-life).
• Mixed tire models or constructions that cause different actual diameters, even at the same size spec.
• Directional or staggered setups that limit rotation options and raise mismatch risks.
• OEM guidance explicitly calling for four-at-once on your specific AWD system.

In practice, many AWD owners end up replacing all four to restore uniformity, especially if their existing set is halfway worn or more.

How to Check and What to Ask Your Shop

A few simple measurements and verifications can show whether a single-tire replacement is safe for your vehicle.

1. Measure each tire’s tread depth with a 32nds gauge (inexpensive and widely available).
2. Compare to “new” depth for your tire model (often 9–12/32 inch; ask your dealer or look up specs).
3. Estimate diameter difference: Each 1/32 inch of tread worn reduces tire diameter by about 2/32 inch because the tire wears on both top and bottom.
4. Convert to percentage: Percent difference ≈ (2 × tread-depth difference) ÷ overall tire diameter. For a 28-inch tire, a 4/32 inch wear difference equals ~0.25 inch diameter change, or about 0.9%—too high for most AWD.
5. Verify load/speed ratings and construction matching (same tire model, not just same size).
6. Ask about tire shaving services if you’re slightly over tolerance and want to avoid buying a full set.
7. Finish with alignment and a fresh rotation schedule to keep wear even going forward.

If your calculations are borderline, defer to the stricter guidance from your owner’s manual or dealership—being conservative protects your drivetrain.

Tire Shaving: What It Is and When It Helps

Tire shaving is a machining process that removes tread from a new tire to match the remaining depth of your existing tires, restoring near-identical rolling circumference across the set.

Consider the following benefits of shaving a single tire to match three partially worn tires.

• Preserves AWD health by aligning wheel speeds more closely than an unshaved new tire would.
• Saves money versus buying four new tires when the other three still have useful life.
• Improves handling balance and braking consistency compared with mixing new and half-worn tires.
• Often available for $30–$60 per tire at specialty shops and some national retailers.

If shaving is available and your existing tires still have several 32nds of life, this route can be a cost-effective compromise that protects your AWD components.

Be aware of the limitations before committing to shaving.

• Not all shops offer it; call ahead or ask tire retailers to arrange the service.
• Shaving permanently reduces remaining tread life on the new tire, so timing matters.
• If the existing set is heavily worn, shaving won’t bring a new tire low enough to be worthwhile; at that point, replacing all four is smarter.
• Shaving precision matters; choose an experienced shop to ensure uniformity and balance.

When executed properly and within reasonable tolerances, shaving effectively bridges the gap between a single-tire replacement and a four-tire purchase.

Manufacturer Guidelines and Tolerances

Automakers vary, but themes are consistent: keep rolling circumference very close across all four corners. Many brands and independent experts cite thresholds such as 2/32 inch maximum tread-depth difference or under about 0.5% in rolling circumference. Some are even stricter. Always check your owner’s manual or a dealer service department for vehicle-specific advice.

Temporary Spares on AWD

Compact “donut” spares are for short, slow trips to a repair shop. On AWD, extended use of a temporary spare (or any mismatched tire) can overwork the AWD system. Follow the spare’s speed and distance limits in the manual, and replace or repair the full-size tire promptly.

Cost Considerations

Shaving a single new tire to match can cost far less than buying four tires if your set is still relatively fresh. If your tires are well worn, replacing all four avoids repeat labor and protects the drivetrain. Road-hazard warranties and tire protection plans may pro-rate or discount replacements; ask your retailer to price all options, including shaving, pairing, and full-set replacement.

Bottom Line

You can replace just one tire on an AWD vehicle if—and only if—the new tire’s rolling circumference closely matches the other three (around 2/32 inch tread-depth difference or less, typically under ~0.5% circumference). If the gap is larger, replace all four or shave the new tire to match. When in doubt, follow your manual’s tolerances and prioritize uniformity to protect your AWD system.

Summary

A single-tire replacement on AWD is feasible when the new tire matches the others very closely in size and type. Use a 2/32 inch tread-depth or ~0.5% circumference difference as a typical ceiling, verify exact OEM guidance, and consider tire shaving to match if the remaining tires have moderate wear. Otherwise, replace all four to avoid driveline stress and maintain safe, predictable handling.

Do you really need to replace all four tires on AWD Reddit?

If it’s a fwd, rwd, or 4×4 vehicle you can just throw a used tire on that’s similar in tread to the other side or just replace them in pairs with matching tires. However if it’s an awd vehicle you will need to swap all 4 if not you can damage stuff and it can lead to costly repairs.

Do all four tires need to be the same on 4WD?

Yes, 4-wheel drive (4WD) and all-wheel drive (AWD) vehicles require all four tires to be the same brand, size, type, and tread depth to prevent premature wear and potential damage to the drivetrain components, such as differentials and the transfer case. Mismatched tires can cause different rotational speeds, leading the AWD system to work harder and struggle to distribute power, which can result in costly repairs and compromised vehicle handling.
 
Why tire uniformity is critical for AWD/4WD systems:

• Different rotational speeds: Tires with varying tread depths or sizes will rotate at different speeds. 
• Drivetrain strain: The AWD/4WD system detects this speed difference and attempts to compensate, causing continuous strain on the differentials, transfer case, and other components. 
• Component damage: This constant work can lead to premature wear and potential failure of expensive parts like the transmission and differentials. 

When replacing tires:

• Replace all four: For AWD/4WD vehicles, it’s best practice to replace all four tires at the same time to ensure uniformity. 
• If replacing one or two: If you must replace only one or two tires, you may need to consult your owner’s manual or a tire professional for specific guidance. 
• “Shaving” a tire: In some cases, if the other three tires are in good condition, a tire shop can “shave” a new tire to match the tread depth of the older tires, but this is a temporary solution as the shaved tire will wear differently over time. 
• Check the owner’s manual: Always refer to your vehicle’s owner’s manual for specific recommendations on tire replacement and limitations on tread depth differences. 

Can you replace just one tire on an all-wheel drive car?

No, you should not replace just one tire on an all-wheel drive (AWD) vehicle because the difference in diameter and tread depth between the new and old tires will cause uneven rotation and put excessive stress on the drivetrain’s differential and transfer case, leading to premature wear and expensive damage. To maintain the health of your AWD system, you must replace all four tires simultaneously or ensure the new tire’s circumference is within a very small tolerance of the other three, often by having it “shaved” down to match the existing tires’ diameter. 
This video explains why you should not replace just one tire on an AWD car: 58sFlatironsTuningYouTube · Mar 3, 2023
Why one tire is problematic

• Uneven drivetrain stress: Opens in new tabAWD systems are designed to have all four tires rotating at the same speed to distribute power evenly. 
• Differential and transfer case damage: Opens in new tabA mismatch in tire diameter forces the differentials and transfer case to constantly work to compensate, leading to overheating and premature wear on these expensive components. 

What to do instead

1. Replace all four tires: This is the safest and most recommended option for AWD vehicles. 
2. Use tire shaving: If budget is a concern and the other tires have sufficient tread, a tire professional can “shave” the new tire down to match the circumference of the existing tires. This ensures they all have a similar diameter. 
3. Check your owner’s manual: Your vehicle’s owner’s manual will specify the maximum allowable difference in tread depth or circumference. 

This video explains when you need to replace all four tires on an AWD car: 35sKurt of TradesYouTube · Dec 5, 2024

Do you have to replace two tires with AWD?

Drivers with an AWD vehicle should refer to their owner’s manual for specific guidance on tire replacement. It’s always best to use four tires from the same brand—and the same model—on a vehicle. Unless specified by the automaker, tires should be the same size and have the same speed rating and load index.