Read the size from left to right
225 = nominal section width in millimeters. 65 = sidewall height as 65% of section width. R = radial construction. 17 = wheel diameter in inches.
The separate load index and speed symbol matter too. Always meet the vehicle manufacturer’s minimum requirements; the size alone does not prove a tire is suitable.
Why different sizes change the speedometer
Approximate overall tire diameter is wheel diameter plus twice the sidewall height. When that diameter changes, the wheel turns a different number of times over the same distance. That can change speedometer and odometer readings, effective gearing and clearance.
Compare candidate sizes with the tire-size tool. A diameter match is only a starting point: actual dimensions vary among tire models, and vehicle-specific requirements still apply.
What matters beyond diameter
- Wheel width: confirm the tire maker’s approved rim-width range.
- Load and speed: meet the vehicle’s specifications and expected conditions.
- Use: all-season, summer and winter tires serve different conditions.
- Axle and AWD requirements: mismatched tire circumference can create problems on some drivetrains. Follow the owner's manual.
- Quantity: check whether the online price is for one tire, a pair or four tires.
A smarter way to buy tires
- Read the original tire size and manufacturer placard.
- Confirm any alternative size is approved for the specific car and wheel.
- Compare load index, speed rating, season and approved wheel widths.
- Look at the price per tire, mounting, balancing, disposal and delivery costs.
- Save the exact products and quantities to your build.
Fitment details vary by vehicle, trim, equipment and product. Noxlane guides are general information, not manufacturer approval. Check specifications and safety-critical work with the appropriate manufacturer or qualified professional.