Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
145/70r12 vs 135/80r12 Tire Comparison Side By Side
  145/70-12 135/80-12 Difference
Diameter inches (mm) 19.99 (507.8) 20.5 (520.8) 0.51 (13) 2.6%
Width inches (mm) 5.71 (145) 5.31 (135) -0.39 (-10) -6.9%
Circum. inches (mm) 62.81 (1595.3) 64.42 (1636.14) 1.61 (40.84) 2.6%
Sidewall Height inches (mm) 4 (101.5) 4.25 (108) 0.26 (6.5) 6.4%
Revolutions per mile (km) 1008.8 (626.84) 983.62 (611.19) -25.18 (-15.65) -2.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)20.51 mph (33.01 km/h)
25 mph (40.23 km/h)25.64 mph (41.26 km/h)
30 mph (48.28 km/h)30.77 mph (49.52 km/h)
35 mph (56.33 km/h)35.9 mph (57.77 km/h)
40 mph (64.37 km/h)41.02 mph (66.02 km/h)
45 mph (72.42 km/h)46.15 mph (74.27 km/h)
50 mph (80.47 km/h)51.28 mph (82.53 km/h)
55 mph (88.51 km/h)56.41 mph (90.78 km/h)
60 mph (96.56 km/h)61.54 mph (99.03 km/h)
65 mph (104.61 km/h)66.66 mph (107.29 km/h)
70 mph (112.65 km/h)71.79 mph (115.54 km/h)
75 mph (120.7 km/h)76.92 mph (123.79 km/h)
80 mph (128.75 km/h)82.05 mph (132.04 km/h)
85 mph (136.79 km/h)87.18 mph (140.3 km/h)
90 mph (144.84 km/h)92.3 mph (148.55 km/h)
95 mph (152.89 km/h)97.43 mph (156.8 km/h)
100 mph (160.93 km/h)102.56 mph (165.05 km/h)

Gear Ratio / RPMs for New Tire (@ 65 mph)
2.35 2.73 2.94 3.07 3.21 3.31 3.42 3.55 3.73 3.91 4.11 4.27 4.56 4.88 5.13 5.29 5.38 5.71 6.17 7.17
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Better Fuel Economy Factory Ratios Increased Power

Most Popular 145/70-R12 Comparisons

To Top