How to Choose the Right Tire Size

1. Find your original size

The size fitted at the factory is on the sticker inside the driver's door, in the owner's manual and on the tire sidewall. Use it as the reference for any change.

2. Keep the overall diameter close

Compare the new size with the original in the calculator. Aim for a diameter within about 3%, and preferably within 1 to 2% for everyday driving.

3. Match the rim

The rim diameter must match the tire exactly, and the rim width must be in the range approved for the tire width. Wider tires on narrow rims bulge and handle poorly.

4. Check load index and speed rating

The number and letter after the size, such as 91V, are the load index and speed rating. The new tire must meet or exceed the values your vehicle requires.

5. Check clearance

Turn the steering to full lock and check the space to the suspension, brake lines and wheel arch. A tire shop can test fit before you buy a full set.

Checklist

Before you change tire size, check these points:

• The overall diameter is within 3% of the original.
• The rim diameter matches and the rim width suits the tire.
• The load index and speed rating meet your vehicle's requirement.
• There is enough clearance at full steering lock and full suspension travel.
• Your local rules and insurance accept the new size.
• The tire pressure is set for the new size, following the tire maker's guidance.