Tire Size Calculator

Tire Size Finder (optional):

Stock Sizes

  • 255/75-16

Plus Sizes

  • 255/75-16

Accepts P-Metric and Inches
/ R
/ R
185/65r15 vs 175/70r14 Tire Comparison Side By Side
  185/65-15 175/70-14 Difference
Diameter inches (mm) 24.47 (621.5) 23.65 (600.6) -0.82 (-20.9) -3.4%
Width inches (mm) 7.28 (185) 6.89 (175) -0.39 (-10) -5.4%
Circum. inches (mm) 76.87 (1952.5) 74.29 (1886.84) -2.59 (-65.66) -3.4%
Sidewall Height inches (mm) 4.73 (120.25) 4.82 (122.5) 0.09 (2.25) 1.9%
Revolutions per mile (km) 824.25 (512.16) 852.93 (529.99) 28.68 (17.82) 3.5%

Speedometer Difference

Speedo Reading Actual Speed
20 mph (32.19 km/h)19.33 mph (31.1 km/h)
25 mph (40.23 km/h)24.16 mph (38.88 km/h)
30 mph (48.28 km/h)28.99 mph (46.66 km/h)
35 mph (56.33 km/h)33.82 mph (54.43 km/h)
40 mph (64.37 km/h)38.65 mph (62.21 km/h)
45 mph (72.42 km/h)43.49 mph (69.99 km/h)
50 mph (80.47 km/h)48.32 mph (77.76 km/h)
55 mph (88.51 km/h)53.15 mph (85.54 km/h)
60 mph (96.56 km/h)57.98 mph (93.31 km/h)
65 mph (104.61 km/h)62.81 mph (101.09 km/h)
70 mph (112.65 km/h)67.65 mph (108.87 km/h)
75 mph (120.7 km/h)72.48 mph (116.64 km/h)
80 mph (128.75 km/h)77.31 mph (124.42 km/h)
85 mph (136.79 km/h)82.14 mph (132.19 km/h)
90 mph (144.84 km/h)86.97 mph (139.97 km/h)
95 mph (152.89 km/h)91.81 mph (147.75 km/h)
100 mph (160.93 km/h)96.64 mph (155.52 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
21712522271528362965305731593279344536113796394442124507473848864969527456996622
Better Fuel Economy Factory Ratios Increased Power

Most Popular 185/65-R15 Comparisons

To Top