275/55R20 vs 285/55R20Tire Size Comparison

Safe

The 1.4% diameter difference is within the accepted 3% tolerance.

275/55R20811mm dia285/55R20822mm dia+5.5mm

Comparison Details

Overall Diameter810.5 vs 821.5 mm (+11.0 mm)
Diameter Difference+1.36%
Section Width275 vs 285 mm (+10 mm)
Sidewall Height151.3 vs 156.8 mm (+5.5 mm)
Circumference2546.3 vs 2580.8 mm
Clearance Change+5.5 mm
Speedometer Error+1.36%
Revs/Mile632 vs 624

Speedometer Correction

When switching from 275/55R20 to 285/55R20, your speedometer will differ from actual speed.

SpeedometerActual SpeedDifference
30 km/h30.4 km/h+0.4 km/h
40 km/h40.5 km/h+0.5 km/h
50 km/h50.7 km/h+0.7 km/h
60 km/h60.8 km/h+0.8 km/h
70 km/h71.0 km/h+1.0 km/h
80 km/h81.1 km/h+1.1 km/h
90 km/h91.2 km/h+1.2 km/h
100 km/h101.4 km/h+1.4 km/h
110 km/h111.5 km/h+1.5 km/h
120 km/h121.6 km/h+1.6 km/h
130 km/h131.8 km/h+1.8 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

275/55R20
Full specifications, compatible vehicles, and alternatives
285/55R20
Full specifications, compatible vehicles, and alternatives

Practical Guidance

Switching from 275/55R20 to 285/55R20 is within the industry-accepted 3% diameter tolerance. Your speedometer, ABS, and traction control should function normally. Both sizes fit the same 20-inch rim, so no wheel change is needed.

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 1.36%, width changes by 10mm.

Speedometer error will be 1.36%. At an indicated 100 km/h, actual speed is about 101.4 km/h.

Ground clearance changes by +5.5mm per side.