275/60R20 vs 275/55R20 Side-by-side tire size comparison with specs and compatibility

275/60R20⌀ 838mm275/55R20⌀ 811mm-13.8mm
Compatibility
-3.28% diameter difference
⚠ Swap with Caution

This tire swap is between 3-5% diameter difference. Check for fender clearance and be aware of speedometer error. May require recalibration.

Full Specifications Comparison

Specification 275/60R20 275/55R20 Difference
Overall Diameter 838 mm (33") 810.5 mm (31.9") -27.5 mm
Section Width 275 mm (10.8") 275 mm (10.8") 0 mm
Sidewall Height 165 mm 151.3 mm -13.7 mm
Circumference 2632.7 mm 2546.3 mm -86.4 mm
Revolutions/Mile 611 632 +21
Aspect Ratio 60% 55% -5%
Rim Diameter 20" 20" 0"

Key Impact Summary

Ground Clearance
-13.7 mm
Speedometer Error
-3.28%
Width Change
0 mm
Sidewall Change
-13.7 mm

Speedometer Correction Table

When switching from 275/60R20 to 275/55R20, your speedometer will over-read. Here is the correction at common speeds:

Speedometer Shows Actual Speed (mph) Difference
30 mph 29 mph -1 mph
40 mph 38.7 mph -1.3 mph
50 mph 48.4 mph -1.6 mph
60 mph 58 mph -2 mph
70 mph 67.7 mph -2.3 mph
80 mph 77.4 mph -2.6 mph
90 mph 87 mph -3 mph
100 mph 96.7 mph -3.3 mph
110 mph 106.4 mph -3.6 mph
120 mph 116.1 mph -3.9 mph

What This Swap Means

Shorter sidewall: The 13.7mm decrease in sidewall height improves steering response and cornering precision. However, ride quality becomes firmer and the wheels are more vulnerable to pothole damage. This is a common trade-off when upsizing wheels (plus-sizing).

Ground clearance: Decreases by 13.7mm, lowering the center of gravity slightly which can improve handling stability.

Vehicles Using 275/60R20

Vehicles Using 275/55R20

Related Comparisons

Individual Tire Specs

Frequently Asked Questions

This swap requires caution. The diameter difference is -3.28% (-27.5mm). This exceeds the recommended 3% threshold and may affect speedometer accuracy, ABS calibration, and could cause clearance issues.
Switching from 275/60R20 to 275/55R20 creates a -3.28% speedometer error. Your actual speed will be slower than displayed — at an indicated 60 mph, you'll actually be going 58.0 mph.
Switching from 275/60R20 to 275/55R20 changes ground clearance by -13.7mm. The vehicle will sit 13.7mm lower. Ground clearance change equals half the overall diameter difference.