What happens if I change only one tire?

Replacing just one tire is usually not recommended; it can upset handling balance, increase braking distances, and, on all-wheel-drive vehicles, risk expensive drivetrain damage. In limited cases—when the new tire closely matches the others in brand, model, size, and tread depth—it can be acceptable, but most experts advise replacing at least two tires (on the same axle) or all four for AWD.

Why one new tire can cause problems

Even small differences in tire diameter and grip can change how your vehicle steers, brakes, and how its electronic safety systems behave. A new tire has deeper tread and a slightly larger rolling circumference than a worn tire, which can cause uneven traction and stability issues, especially in wet conditions.

The mechanics behind mismatched tires

New tires are taller because they have more tread. That larger circumference means they rotate fewer times per mile than worn tires. On modern cars, anti-lock brakes (ABS), traction control, and stability control compare wheel speeds; a mismatch can trigger false interventions. On AWD vehicles, the center differential or transfer case can be forced to “work” constantly to compensate, generating heat and wear.

The most common issues you may notice when mixing one fresh tire with three worn ones include the following.

• Handling imbalance: Different grip levels left-to-right can induce pulling, uneven cornering response, or fishtailing in emergency maneuvers.
• Longer wet stopping distances: The deeper-tread tire resists hydroplaning better, so the vehicle can yaw as one side grips more than the other.
• Electronic nannies working overtime: ABS/ESC may engage prematurely due to wheel-speed differences, sometimes illuminating warning lights.
• Drivetrain stress in AWD: Constant slip across the center differential or clutch pack increases heat and wear, risking costly damage.
• Uneven wear patterns: The new tire may wear faster as it shoulders more traction duties, reducing its lifespan.

While some drivers may not notice subtle differences in ideal conditions, these mismatches tend to show up at the worst times—heavy rain, hard braking, or evasive maneuvers.

AWD/4WD versus FWD/RWD: What’s different

Your drivetrain type determines how risky a single-tire replacement is. AWD/4WD powertrains are far less tolerant of rolling-diameter differences than two-wheel-drive layouts, which primarily suffer handling and braking imbalances rather than mechanical stress.

AWD and 4WD: Why one tire is a bigger deal

All-wheel-drive systems rely on similar rolling circumferences to prevent constant slip between axles. A single taller tire upsets this balance.

• Center differential/transfer case wear: Continuous compensation for one larger (new) tire can overheat clutches and shear fluid.
• Manufacturer limits: Many automakers (e.g., Subaru and others) require all four tires to be within about 2/32 inch of tread depth or within roughly 0.5% rolling circumference.
• Warranty risk: Drivetrain damage linked to mismatched tires can be excluded from warranty coverage.

If you drive an AWD/4WD vehicle and have one damaged tire, shops often recommend replacing all four—or shaving the new tire to match the remaining tread depth.

FWD and RWD: Concerns remain, but are different

Two-wheel-drive cars are more forgiving mechanically, but one new tire still creates stability and braking asymmetries, especially in wet or snowy conditions.

• Replace in pairs: The standard recommendation is to replace at least two tires on the same axle.
• Best tires on the rear: Regardless of drivetrain, industry guidance places the newest/deepest-tread tires on the rear axle to reduce oversteer and spin-outs in emergencies.
• Shop policies: Many reputable tire shops refuse to install a single tire because of safety and liability concerns.

While a two-wheel-drive vehicle may not break parts from a single new tire, it can still become less stable in critical situations.

When changing only one tire can be acceptable

There are narrow circumstances where one-tire replacement can be done with minimal risk. These depend on strict matching and small differences in tread depth and diameter.

• Very low wear on the other tires: If the existing tires are nearly new and within about 2/32 inch tread depth of a new tire, one-for-one replacement may be acceptable (check your owner’s manual or manufacturer guidance).
• Exact match: Use the same brand, model, size, speed rating, load index, and tire type (e.g., all-season vs. summer). Mixing models can change handling even if sizes match.
• AWD tire shaving: A shop can shave the new tire’s tread to match the remaining tread depth, maintaining rolling-circumference parity.
• Placement: If a single tire must be installed, the best practice is to place the newest/deepest tread on the rear axle and move the best of the remaining tires to pair it, putting the more worn pair on the front.
• No mixed constructions: Don’t mix run-flat with non–run-flat, or P-metric with LT, on the same vehicle unless the manufacturer explicitly allows it.

Even when conditions are met, monitor handling and tire pressures closely after installation, and consider a follow-up inspection and rotation.

What to do instead of replacing just one

If budget and availability allow, there are safer alternatives that preserve handling balance and protect your drivetrain.

• Replace two tires on the same axle and mount them on the rear; move the existing tires to the front.
• Replace all four on AWD/4WD vehicles when the remaining tread is notably lower or when the manual specifies strict matching.
• Use tire shaving to match a single new tire to lightly worn mates on AWD if the others are still in good shape.
• Leverage road-hazard coverage or insurance if a premature failure destroyed one tire.
• Schedule alignment and balance to prevent rapid or uneven wear on new tires.

These options typically cost more upfront but reduce the risk of instability or drivetrain repairs later.

How to check compatibility before deciding

A quick assessment can tell you whether one-tire replacement is feasible or risky, especially on AWD vehicles.

• Measure tread depth: Compare the remaining tires to new-tire depth. Differences larger than about 2/32 inch (≈1.6 mm) are often too great for AWD; FWD/RWD may tolerate slightly more but still prefer pairs.
• Check rolling circumference: Some manufacturers specify a max difference (often around 0.5% to 1.0%). A tire shop can measure circumference or rolling radius.
• Verify specs: Match brand, model, size, speed rating, load index, and construction type across all corners.
• Consult the owner’s manual: Follow any AWD/4WD-specific replacement guidance; some brands are stricter than others.
• Inspect condition: Ensure remaining tires are free of cupping, sidewall damage, or age-related cracking; don’t pair a new tire with unsafe mates.
• Calibrate systems: After replacement, set pressures to door-jamb specs, perform TPMS relearn if required, and consider an alignment check.

If your measurements exceed the manufacturer’s limits, replacing two or four tires—or shaving the new tire—is the prudent choice.

Costs and warranty implications

Choosing a single replacement to save money can backfire if it leads to component wear or safety issues. Understanding the financial trade-offs helps avoid bigger bills later.

• AWD repairs: Overheated clutches or transfer cases can cost four figures to repair or replace.
• Warranty concerns: Evidence of mismatched tires can be grounds for denying related drivetrain claims.
• Premature wear: A lone new tire may wear faster if it’s constantly compensating for traction imbalances.
• Resale and inspections: Mismatched tires can be flagged in pre-sale inspections or lease returns.

While replacing more than one tire is more expensive up front, it often protects the vehicle and your warranty status.

Bottom line

Replacing only one tire is generally a last resort. It can be acceptable if the surviving tires are almost new and you can exactly match specifications and tread depth (or have the new tire shaved), but most drivers should plan on replacing tires in pairs—and all four on many AWD vehicles. When in doubt, follow your owner’s manual and your tire shop’s safety policies.

Summary

One-tire replacement can compromise safety and, on AWD/4WD, cause mechanical damage. It’s typically better to replace tires in pairs or all four, place the best tires on the rear, and match brand/model/specs. If a single replacement is unavoidable, ensure the new tire closely matches the others in tread depth and construction, or have it shaved to fit—especially on AWD. Always verify manufacturer limits and consider alignment and TPMS procedures after installation.

What happens if you only change one tire?

Replacing only one tire is generally not recommended, especially for all-wheel-drive (AWD) vehicles, as it can cause uneven wear, poor handling, and potentially damage the drivetrain, particularly the center differential on AWD cars. While you might get away with it on front- or rear-wheel-drive vehicles if the other tires are very new, significant differences in tread depth between the new and old tires can lead to imbalances in traction and stability, creating unpredictable handling and affecting the performance of safety systems like ABS and traction control. 
Risks of Replacing Just One Tire

• Uneven Performance and Stability: A new tire with a deep tread grips the road differently than a worn tire, creating an imbalance that can lead to less stable handling, especially in wet or slippery conditions. 
• Drivetrain Damage: On AWD vehicles, a difference in tire diameter due to varying tread depths can cause the center differential to work harder to reconcile the speed difference between the front and rear axles, leading to accelerated wear and potential damage. 
• Faulty System Signals: The difference in tire revolution rates can send false information to the vehicle’s electronic systems, including anti-lock brakes (ABS) and traction control, which rely on consistent signals from all four tires. 
• Accelerated Wear on Other Components: An imbalance in tire grip and rolling resistance can also lead to accelerated and uneven wear on the other tires and potentially affect your car’s suspension. 

When It Might Be Acceptable

• Minimal Tread Difference: Opens in new tabIf your other tires are very new and their tread depth is only slightly less than the new tire (within 2/32” to 4/32” of each other), replacing a single tire might be an option for non-AWD vehicles. 
• Front- or Rear-Wheel-Drive: Opens in new tabThe risk is generally lower for front-wheel-drive or rear-wheel-drive cars compared to AWD vehicles, but it still carries risks of uneven wear and handling issues. 

Best Practices

• Check Your Owner’s Manual: Always consult your vehicle’s owner’s manual for specific recommendations, especially for AWD vehicles, as some manufacturers advise against replacing fewer than four tires. 
• Replace Tires in Pairs: If replacing only one tire is unavoidable, consider replacing the two tires on the same axle to maintain some level of uniformity. 
• Consider the Penny Test: Use the penny test to check the tread depth of your existing tires. If they are significantly worn (less than 4/32” of an inch), replacing all four tires is a safer bet. 

What is the 3% rule for tires?

If they’re too large, they could scrape on the inside of the fender every time you make a turn. As a general rule, you want replacement tires that are within 3 percent of the diameter (height) measurement of the tires originally on your vehicle.

What happens if you don’t replace tires in pairs?

Uneven Tread Depth = Uneven Performance
New tires have deeper treads than worn ones, which means they grip the road differently. If you install just one new tire, your car will have an imbalance in traction, especially in wet or slippery conditions.

Is it okay to replace one tire with a different brand?

No, it is not recommended to have only one tire of a different brand; you should always aim to use four matching tires, or at a minimum, two matching tires of the same brand, size, tread pattern, and performance ratings (load index and speed rating). While you may be able to drive with a single mismatched tire, it can lead to unbalanced handling, reduced braking and traction, uneven tire wear, and potential safety issues, especially in emergency situations or on wet or snowy roads. 
Why you should avoid mixing tire brands

• Inconsistent Performance: Different brands can have varying materials, designs, and tread patterns, affecting how they grip the road and handle. 
• Uneven Wear: Mismatched tires will wear down at different rates, potentially leading to an unbalanced vehicle. 
• Compromised Safety: Mismatched tires can reduce braking effectiveness, alter the vehicle’s handling, and make it harder to control in critical moments. 
• Tire Characteristics: Even tires of the same size can differ slightly in their overall dimensions and construction, which can create imbalances. 

What to do instead

• Replace all four tires: This is the ideal solution for consistent performance and safety. 
• Replace in pairs: If you can’t replace all four, replace the two worn tires with a new pair of the same brand and model as the existing ones on the same axle. 
• Match tire specifications: At the very least, ensure that any new tires have the same size, tread pattern, load index, and speed rating as the other tires on the vehicle.