Should You Replace All Four Tires on Your AWD Vehicle at the Same Time?

In most cases, yes. All-wheel drive (AWD) systems are designed to work with four tires that closely match in size and tread depth. Replacing only two tires can create differences in wheel speed that affect how the system distributes power. Here’s why.

Replacing All Four Tires Is a Good Idea

While it may be tempting to replace only the most-worn tires, replacing all four at the same time is often recommended by most AWD vehicle manufacturers. That’s because the front tires on an AWD vehicle often wear more quickly than those on the rear axle because they handle most of the braking and steering. Other factors that can accelerate wear include misalignment, aggressive driving, underinflated tires, and not rotating tires regularly.

Speaking of rotations, getting your tires rotated every 5,000 miles can help prolong their tread life and save you money. When you buy tires for your AWD vehicle at Les Schwab, those rotations are free. Schedule yours today.

Key Takeaways for AWD Tire Replacement

• Front tires on all-wheel-drive (AWD) vehicles often wear more quickly than the back tires.
• Mismatched tires can create differences in wheel speed. This can stress AWD drivetrain components.
• Replacing all four tires with the same brand, size, and type helps maintain proper AWD performance.
• Excessive tread depth differences between tires can cause issues.
• Always check your owner’s manual for manufacturer-specific limits.

Mismatching Tires May Cause Damage to Your AWD Vehicle

Replacing just one or two tires on an AWD vehicle could cause unnecessary wear and tear on your drivetrain, or confuse the traction control system into thinking that you are frequently losing traction.

A new tire is often larger in diameter than one of the same brand, type and size that’s part way through its tread life. This means there’s a measurable difference in tire tread depth and tire circumference that may affect your vehicle’s performance.

How Tread Depth Differences Can Affect Tire Rotation

To understand why this matters, imagine two people out for a walk. Both are wearing fitness trackers that monitor the distance they travel and the number of steps they take. However, one of them is taller and has longer legs. By the end of the workout, they might cover the same distance, but the taller walker will have taken less steps to get there.

The same is true for mismatched tires. A taller tire with more tread depth travels more distance in a single revolution than a shorter tire with less tread depth. In order to keep up, the tire with less tread depth will spin faster and have more revolutions than the tire with more tread depth.

Tire Tread Depth Comparison

Here’s an illustration showing how even if a tire is labeled the same size, the tire with less tread (the used tire) will revolve more times than the newer tire with more tread depth.

How Mismatched Tires Can Affect Your AWD Drivetrain

So why is mixing new and used tires a potential problem for your AWD vehicle? First, even a slight difference in diameter between front and rear tires on your AWD vehicle can mean trouble for the drivetrain. These are the components of the car that transfer the power from the engine to the wheels that move the vehicle forward.

If any tire or tires are spinning faster than any of the others, your car’s electronics may think a tire is slipping, and could transfer power incorrectly when compared to your current driving conditions. Most AWD systems in today’s cars include sensors at each wheel that monitor traction and wheel speed many times per second. This is what allows the AWD system to adapt to slick conditions, by sending power to whatever wheel(s) have the most traction.

What Happens When AWD Systems Detect Different Wheel Speeds

When smaller tires are spinning faster, some systems may put your vehicle into four-wheel lock, the mode used for driving in slippery conditions. Driving in that mode on pavement or at higher speeds may cause damage to your vehicle’s drivetrain and cost you money in repairs.

Follow Your Owner’s Manual and Expert Advice

If any of your tires are due to be replaced, it’s absolutely essential to check your vehicle’s owner’s manual for recommendations. Look in the tires and transmission sections. Not following these recommendations may result in costly damage to some of the most important driving components of your car, like the transmission. Any reputable tire dealer will follow car manufacturer recommendations.

At Les Schwab Tire Centers, we use a tread depth gauge to accurately measure the tread depth as a complimentary service. We can then help you decide if a full set of new tires would be best.

Les Schwab Tip: Use the penny test at home to test your tire’s tread depth.

Schedule a Tire Inspection at Les Schwab

Replacing all four tires with the same size and similar tread depth really can make your daily drives and weekend adventures a lot more enjoyable and safe. Not sure if your tires match? Stop by your nearby Les Schwab and we’ll give them a quick visual inspection and offer recommendations to help you decide if a new set of tires is the right choice for you.