About the 185/70R15 Tire

The 185/70R15 is a common tire size for compact and economy vehicles such as Honda Fit, Toyota Yaris, and Kia Rio.

With a 129.5 mm sidewall (70% aspect ratio), this tire provides a smooth, cushioned ride that absorbs road imperfections well — ideal for daily commuting and highway cruising.

Compared to the baseline 195/65R15, this tire's overall diameter differs by +0.9% — a speedometer calibrated for 195/65R15 would read 99.1 km/h at an actual 100 km/h.

When replacing, verify that your wheel well can accommodate the 640.0 mm overall diameter. Keep speedometer deviation within ±3% for safety and legal compliance.

Tire Measurements

Tire Code185/70R15
Section Width185 mm
Aspect Ratio70%
Rim Diameter15"
Sidewall Height129.5 mm
Overall Diameter640.0 mm / 25.20"
Circumference2010.6 mm / 79.16"
Revolutions per km497.4
Revolutions per mile800.4

Adjacent Size Comparison

Tire Code OD (mm)Δ mmΔ % Speedo at 100 km/h
185/60R15 603.0 -37.0 -5.8% 106.1
185/65R15 621.5 -18.5 -2.9% 103.0
175/70R15 626.0 -14.0 -2.2% 102.2
185/70R15 (current) 640.0 100.0
195/70R15 654.0 +14.0 +2.2% 97.9

Frequently Asked Questions

What is the overall diameter of a 185/70R15 tire?
The overall diameter is 640.0 mm (25.20 in), with a 129.5 mm sidewall on a 15-inch rim.
How many revolutions per kilometer does a 185/70R15 tire make?
It makes 497.4 revolutions per kilometer, with a circumference of 2010.6 mm.
What vehicles commonly use 185/70R15 tires?
The 185/70R15 is standard OEM equipment on compact and economy vehicles such as Honda Fit, Toyota Yaris, and Kia Rio. Always check your owner's manual or door placard before switching sizes.

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