265/75R16 vs 265/65R18 Tire Comparison

265/75R16 has nominal diameter 31.6496 in; 265/65R18 has 31.5630 in. Diameter changes -0.274%; at indicated 60 mph the new nominal speed is 59.836 mph. Selected standard passenger and common truck/SUV tire sizes, not a verified market-popularity ranking. Nominal dimensions do not guarantee vehicle fitment.

265/75R16 vs 265/65R18 Tire Comparison reference last updated · reference source

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Dated static reference; no live data is fetched. Verify current source values and assumptions before relying on results.

What this tool does

265/75R16 has nominal diameter 31.6496 in; 265/65R18 has 31.5630 in. Diameter changes -0.274%; at indicated 60 mph the new nominal speed is 59.836 mph. Selected standard passenger and common truck/SUV tire sizes, not a verified market-popularity ranking. Nominal dimensions do not guarantee vehicle fitment.

How to use the 265/75R16 vs 265/65R18 Tire Comparison

  1. Check Tire width (mm): 265.
  2. Check Tire aspect ratio (%): 75.
  3. Check Tire rim diameter (inches): 16.
  4. Check Tire B width (mm): 265.
  5. Check Tire B aspect ratio (%): 65.
  6. Check Tire B rim diameter (inches): 18.
  7. Check Indicated speed (mph): 60.
  8. Review the 265/75R16 vs 265/65R18 Tire Comparison result and its exact-value comparison table.
  9. Verify assumptions before applying the result.

Formula

difference%=(diameterB/diameterA−1)×100; actual speed=indicated speed×diameterB/diameterA
width
Tire width (mm)
aspect
Tire aspect ratio (%)
rim
Tire rim diameter (inches)
widthB
Tire B width (mm)
aspectB
Tire B aspect ratio (%)
rimB
Tire B rim diameter (inches)
speed
Indicated speed (mph)

Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.

Worked example

265/75R16 vs 265/65R18 Tire Comparison: Tire width (mm) = 265; Tire aspect ratio (%) = 75; Tire rim diameter (inches) = 16; Tire B width (mm) = 265; Tire B aspect ratio (%) = 65; Tire B rim diameter (inches) = 18; Indicated speed (mph) = 60. 265/75R16 has nominal diameter 31.6496 in; 265/65R18 has 31.5630 in. Diameter changes -0.274%; at indicated 60 mph the new nominal speed is 59.836 mph. Selected standard passenger and common truck/SUV tire sizes, not a verified market-popularity ranking. Nominal dimensions do not guarantee vehicle fitment.

Inputs

  • Tire width (mm)265
  • Tire aspect ratio (%)75
  • Tire rim diameter (inches)16
  • Tire B width (mm)265
  • Tire B aspect ratio (%)65
  • Tire B rim diameter (inches)18
  • Indicated speed (mph)60

Result

  • Diameter difference (%)-0.27
  • Actual speed (mph)59.84
  • Ground clearance change-0.04 in

265/75R16 versus 265/65R18

MeasurementOriginal tireNew tire
Diameter (in)31.649606299212631.562992125984252
Sidewall (in)7.82480314960636.781496062992126
Circumference (in)99.4301706386155599.1580641883046
Revolutions/mile637.2311300790725638.9797997637102
Speed at indicated 30 mph3029.917900236347805
Speed at indicated 45 mph4544.87685035452171
Speed at indicated 60 mph6059.83580047269561
Speed at indicated 70 mph7069.80843388481154

Results explained

Diameter difference (%)
Diameter difference (%) from the formula above. Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.
Actual speed (mph)
Actual speed (mph) from the formula above. Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.
Ground clearance change
Ground clearance change from the formula above, expressed in in before metric conversion. Assumes the speedometer was calibrated to the original tire. Does not check wheel offset, width or clearance.

Frequently asked questions

Diameter difference is -0.0866 inches (-0.274%).

7.8248 and 6.7815 inches respectively.

Nominal actual speed becomes 59.836 mph if calibrated to 265/75R16.

637.23 versus 638.98 geometric revolutions/mile.

This comparison cannot confirm fitment. Ground clearance changes -0.04330708661417404 in geometrically; verify wheel width, offsets, load/speed ratings and manufacturer requirements.