ElpiAuto

Tire size comparison

275/55R20 vs 275/60R20

275/60R20 is 1.08″ (28 mm) taller than 275/55R20, a 3.4% difference in overall diameter — outside the ±3% band, so expect the speedometer to drift and check for rubbing before fitting.

31.91″32.99″A  275/55R20B  275/60R20Both sizes to scale · dimension lines in inches
Measurement275/55R20275/60R20Difference%
Overall diameter31.91″32.99″+1.08″+3.4%
Section width10.83″10.83″
Sidewall height5.95″6.50″+0.54″+9.1%
Circumference100.25″103.65″+3.40″+3.4%
Revs per mile632.0611.3−20.7−3.3%
Revs per km392.7379.8−12.9−3.3%

Speedometer: with 275/55R20 as the original, 275/60R20 makes an indicated 60 mph really about 62.0 mph, and the axle sits ~0.54″ higher.

Reading this comparison

The overall diameter is what matters here: 275/60R20 is the taller tire. It sets ride height, gearing and how far the tire travels per revolution — which is what the speedometer and odometer count. Width and sidewall change fit and feel (a wider tire needs a wider wheel and more clearance; a shorter sidewall sharpens steering) but not the gearing.

Figures are geometric estimates from the size codes; real moulded tires vary by brand by 1–3%. Confirm load rating, wheel width and physical clearance on your vehicle before fitting. To compare any other two sizes, use the tire size comparison tool; to decode one size and see what else fits its wheel, the tire size calculator.

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