Question 1

How do I read tire size like 225/45R17?

Accepted Answer

225 = tread width (mm), 45 = aspect ratio (% of width), R = radial, 17 = wheel diameter (inches).

Question 2

How does tire size affect speedometer?

Accepted Answer

Larger overall diameter reads slower; smaller reads faster. The calculator shows the percent difference.

Question 3

What is the impact on clearance and gearing?

Accepted Answer

Bigger tires can rub and effectively increase gearing; smaller do the opposite. Check clearance and load ratings.

Question 4

Can I put any width on my rim?

Accepted Answer

Rim width range must match tire width; consult tire fitment guides.

Question 5

What about load index and speed rating?

Accepted Answer

Match or exceed OEM specs for safety and legal compliance.

Tire Size Calculator