31x10.50R15 speedometer error table

Speedometer error guide

This seed page compares 31x10.50R15 with nearby popular sizes and shows how each alternative changes indicated speed. The calculation uses the same deterministic tire-geometry engine as the live calculator.

FAQ

Speedometer error guide
This seed page compares 31x10.50R15 with nearby popular sizes and shows how each alternative changes indicated speed. The calculation uses the same deterministic tire-geometry engine as the live calculator.
What should I verify before using this information?
Use TireFitLab values as a sizing reference, then verify the vehicle handbook, tire placard, rim compatibility, load rating, and physical clearance before fitting.
Candidate size Overall diameter Diameter difference Indicated 100 reads as Verdict Compare
31x10.50R15 31.00 in 0% 100 mph Close match Open calculator
31x10.50R16 31.00 in 0.00% 100.0 mph Close match Compare
285/40R22 30.98 in -0.08% 99.9 mph Close match Compare
275/55R19 30.91 in -0.29% 99.7 mph Close match Compare
285/50R20 31.22 in +0.71% 100.7 mph Close match Compare
275/45R21 30.74 in -0.83% 99.2 mph Close match Compare
265/70R16 30.61 in -1.27% 98.7 mph Close match Compare
265/65R17 30.56 in -1.41% 98.6 mph Close match Compare
245/65R18 30.54 in -1.49% 98.5 mph Close match Compare
285/60R18 31.46 in +1.50% 101.5 mph Close match Compare
265/60R18 30.52 in -1.55% 98.5 mph Close match Compare
245/70R17 30.50 in -1.60% 98.4 mph Close match Compare
265/65R18 31.56 in +1.82% 101.8 mph Close match Compare

Seed pages are limited to the public TireFitLab size corpus. The long tail stays gated until demand data supports expansion.

How to read the table

Positive speedometer error means the vehicle travels faster and further than indicated. The tolerance verdict only checks overall diameter; it does not verify load rating, clearance, wheel fitment or local approval.

Related references

Seasonal check

Planning a long summer drive?

Use the budget and running-cost tools before a trip, especially if the current tyres are worn or the replacement size changes diameter.

Estimate tyre budget
Last reviewed: 2026-06-28
What changed
  • Added curated per-size speedometer-error reference tables.