255/60R19 vs 275/55R20Tire Size Comparison

Safe

The 2.8% diameter difference is within the accepted 3% tolerance.

255/60R19789mm dia275/55R20811mm dia+10.9mm

Comparison Details

Overall Diameter788.6 vs 810.5 mm (+21.9 mm)
Diameter Difference+2.78%
Section Width255 vs 275 mm (+20 mm)
Sidewall Height153.0 vs 151.3 mm (-1.7 mm)
Circumference2477.5 vs 2546.3 mm
Clearance Change+10.9 mm
Speedometer Error+2.78%
Revs/Mile650 vs 632

Speedometer Correction

When switching from 255/60R19 to 275/55R20, your speedometer will differ from actual speed.

SpeedometerActual SpeedDifference
30 km/h30.8 km/h+0.8 km/h
40 km/h41.1 km/h+1.1 km/h
50 km/h51.4 km/h+1.4 km/h
60 km/h61.7 km/h+1.7 km/h
70 km/h71.9 km/h+1.9 km/h
80 km/h82.2 km/h+2.2 km/h
90 km/h92.5 km/h+2.5 km/h
100 km/h102.8 km/h+2.8 km/h
110 km/h113.1 km/h+3.1 km/h
120 km/h123.3 km/h+3.3 km/h
130 km/h133.6 km/h+3.6 km/h

Vehicles Using These Sizes

Vehicles with 275/55R20

2026 Ford F-150King Ranch / Platinum / Limited (20")2020 Ford F-150Lariat/King Ranch/Platinum2020 GMC SierraSLE/Elevation2020 GMC SierraSLT/AT4/Denali2025 Infiniti QX80Sensory2026 Jeep WranglerSahara optional / Rubicon X / 4xe (20")2026 Ram 1500Big Horn / Lone Star2026 Ram 1500Laramie2026 Ram 1500Limited / Longhorn / Tungsten2025 Ram 1500Laramie/Longhorn2024 Ram 1500Laramie/Longhorn2023 Ram 1500Laramie/Longhorn/Limited2022 Ram 1500Laramie/Longhorn/Limited2021 Ram 1500Laramie/Longhorn/Limited2020 Ram 1500Laramie/Longhorn/Limited2025 Toyota TundraLimited2025 Toyota TundraTRD Pro/17942024 Toyota TundraLimited/1794/TRD Pro2023 Toyota TundraLimited/1794/TRD Pro2022 Toyota TundraLimited/1794/TRD Pro2021 Toyota TundraLimited/1794/TRD Pro2020 Toyota TundraLimited/1794/TRD Pro

Individual Tire Size Details

255/60R19
Full specifications, compatible vehicles, and alternatives
275/55R20
Full specifications, compatible vehicles, and alternatives

Practical Guidance

Switching from 255/60R19 to 275/55R20 is within the industry-accepted 3% diameter tolerance. Your speedometer, ABS, and traction control should function normally. Note: these sizes require different rim diameters (19" vs 20"), so you will need different wheels.

The 3% diameter tolerance is a widely accepted industry guideline referenced by the ETRTO and most vehicle manufacturers. When in doubt, consult your vehicle's owner's manual or a qualified tire professional. For U.S. tire safety standards and recalls, see the NHTSA Tire Safety page.

Frequently Asked Questions

Safe. The overall diameter differs by 2.78%, width changes by 20mm.

Speedometer error will be 2.78%. At an indicated 100 km/h, actual speed is about 102.8 km/h.

Ground clearance changes by +10.9mm per side.