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3.31 gearing information - tires vs. rpm

tire size vs. rpm and speed

=($A17*I$4*PI()*60)/(I$3*12*5280)

a17 is engine rpm 
I4 is tire diameter  estimated 30.38 for the 31x10.5's...
Pi is pi... :) 3.1416
I3 is the gear ratio... in this case 3.31



Note:   Tire diameter is in INCHES.  Speed in Miles per hour.  Tach = rpm



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Gears: 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31 3.31
Tires: 28.88 29.38 29.88 30.38 30.88 31.38 31.88 32.38 32.88 33.38 33.88 34.38 34.88 35.38 35.88 36.38 36.88 37.38 37.88
tach mph mph mph mph mph mph mph mph mph mph mph mph mph mph mph mph mph mph mph
600 15.57 15.84 16.11 16.38 16.65 16.92 17.19 17.46 17.73 18.00 18.27 18.54 18.81 19.08 19.35 19.62 19.89 20.16 20.43
700 18.17 18.48 18.80 19.11 19.43 19.74 20.06 20.37 20.69 21.00 21.32 21.63 21.94 22.26 22.57 22.89 23.20 23.52 23.83
800 20.77 21.13 21.48 21.84 22.20 22.56 22.92 23.28 23.64 24.00 24.36 24.72 25.08 25.44 25.80 26.16 26.52 26.88 27.24
900 23.36 23.77 24.17 24.57 24.98 25.38 25.79 26.19 26.60 27.00 27.41 27.81 28.21 28.62 29.02 29.43 29.83 30.24 30.64
1000 25.96 26.41 26.86 27.31 27.75 28.20 28.65 29.10 29.55 30.00 30.45 30.90 31.35 31.80 32.25 32.70 33.15 33.60 34.05
1100 28.55 29.05 29.54 30.04 30.53 31.02 31.52 32.01 32.51 33.00 33.50 33.99 34.48 34.98 35.47 35.97 36.46 36.96 37.45
1200 31.15 31.69 32.23 32.77 33.31 33.84 34.38 34.92 35.46 36.00 36.54 37.08 37.62 38.16 38.70 39.24 39.78 40.32 40.86
1300 33.74 34.33 34.91 35.50 36.08 36.67 37.25 37.83 38.42 39.00 39.59 40.17 40.75 41.34 41.92 42.51 43.09 43.68 44.26
1400 36.34 36.97 37.60 38.23 38.86 39.49 40.11 40.74 41.37 42.00 42.63 43.26 43.89 44.52 45.15 45.78 46.41 47.04 47.66
1500 38.94 39.61 40.28 40.96 41.63 42.31 42.98 43.65 44.33 45.00 45.68 46.35 47.02 47.70 48.37 49.05 49.72 50.40 51.07
1600 41.53 42.25 42.97 43.69 44.41 45.13 45.85 46.56 47.28 48.00 48.72 49.44 50.16 50.88 51.60 52.32 53.04 53.75 54.47
1700 44.13 44.89 45.65 46.42 47.18 47.95 48.71 49.47 50.24 51.00 51.77 52.53 53.29 54.06 54.82 55.59 56.35 57.11 57.88
1750 45.42 46.21 47.00 47.78 48.57 49.36 50.14 50.93 51.72 52.50 53.29 54.08 54.86 55.65 56.43 57.22 58.01 58.79 59.58
1850 48.02 48.85 49.68 50.51 51.35 52.18 53.01 53.84 54.67 55.50 56.33 57.17 58.00 58.83 59.66 60.49 61.32 62.15 62.99
1950 50.62 51.49 52.37 53.25 54.12 55.00 55.87 56.75 57.63 58.50 59.38 60.26 61.13 62.01 62.88 63.76 64.64 65.51 66.39
2050 53.21 54.13 55.05 55.98 56.90 57.82 58.74 59.66 60.58 61.50 62.42 63.35 64.27 65.19 66.11 67.03 67.95 68.87 69.79
2150 55.81 56.77 57.74 58.71 59.67 60.64 61.60 62.57 63.54 64.50 65.47 66.44 67.40 68.37 69.33 70.30 71.27 72.23 73.20
2250 58.40 59.41 60.43 61.44 62.45 63.46 64.47 65.48 66.49 67.50 68.51 69.53 70.54 71.55 72.56 73.57 74.58 75.59 76.60
2350 61.00 62.06 63.11 64.17 65.22 66.28 67.34 68.39 69.45 70.50 71.56 72.62 73.67 74.73 75.78 76.84 77.90 78.95 80.01
2450 63.59 64.70 65.80 66.90 68.00 69.10 70.20 71.30 72.40 73.50 74.60 75.71 76.81 77.91 79.01 80.11 81.21 82.31 83.41
2550 66.19 67.34 68.48 69.63 70.77 71.92 73.07 74.21 75.36 76.50 77.65 78.80 79.94 81.09 82.23 83.38 84.53 85.67 86.82
2650 68.79 69.98 71.17 72.36 73.55 74.74 75.93 77.12 78.31 79.50 80.70 81.89 83.08 84.27 85.46 86.65 87.84 89.03 90.22
2750 71.38 72.62 73.85 75.09 76.33 77.56 78.80 80.03 81.27 82.50 83.74 84.98 86.21 87.45 88.68 89.92 91.16 92.39 93.63
2850 73.98 75.26 76.54 77.82 79.10 80.38 81.66 82.94 84.22 85.50 86.79 88.07 89.35 90.63 91.91 93.19 94.47 95.75 97.03
2950 76.57 77.90 79.22 80.55 81.88 83.20 84.53 85.85 87.18 88.50 89.83 91.16 92.48 93.81 95.13 96.46 97.78 99.11 100.44
3050 79.17 80.54 81.91 83.28 84.65 86.02 87.39 88.76 90.13 91.50 92.88 94.25 95.62 96.99 98.36 99.73 101.10 102.47 103.84
3150 81.76 83.18 84.60 86.01 87.43 88.84 90.26 91.67 93.09 94.51 95.92 97.34 98.75 100.17 101.58 103.00 104.41 105.83 107.25
3250 84.36 85.82 87.28 88.74 90.20 91.66 93.12 94.58 96.04 97.51 98.97 100.43 101.89 103.35 104.81 106.27 107.73 109.19 110.65
3350 86.96 88.46 89.97 91.47 92.98 94.48 95.99 97.49 99.00 100.51 102.01 103.52 105.02 106.53 108.03 109.54 111.04 112.55 114.05
3450 89.55 91.10 92.65 94.20 95.75 97.30 98.85 100.40 101.96 103.51 105.06 106.61 108.16 109.71 111.26 112.81 114.36 115.91 117.46
3550 92.15 93.74 95.34 96.93 98.53 100.12 101.72 103.31 104.91 106.51 108.10 109.70 111.29 112.89 114.48 116.08 117.67 119.27 120.86
3650 94.74 96.38 98.02 99.66 101.30 102.94 104.58 106.23 107.87 109.51 111.15 112.79 114.43 116.07 117.71 119.35 120.99 122.63 124.27
3750 97.34 99.02 100.71 102.39 104.08 105.77 107.45 109.14 110.82 112.51 114.19 115.88 117.56 119.25 120.93 122.62 124.30 125.99 127.67
3850 99.93 101.66 103.39 105.13 106.86 108.59 110.32 112.05 113.78 115.51 117.24 118.97 120.70 122.43 124.16 125.89 127.62 129.35 131.08
3950 102.53 104.31 106.08 107.86 109.63 111.41 113.18 114.96 116.73 118.51 120.28 122.06 123.83 125.61 127.38 129.16 130.93 132.71 134.48
4050 105.13 106.95 108.77 110.59 112.41 114.23 116.05 117.87 119.69 121.51 123.33 125.15 126.97 128.79 130.61 132.43 134.25 136.07 137.89
4150 107.72 109.59 111.45 113.32 115.18 117.05 118.91 120.78 122.64 124.51 126.37 128.24 130.10 131.97 133.83 135.70 137.56 139.43 141.29
4250 110.32 112.23 114.14 116.05 117.96 119.87 121.78 123.69 125.60 127.51 129.42 131.33 133.24 135.15 137.06 138.97 140.88 142.79 144.70
4350 112.91 114.87 116.82 118.78 120.73 122.69 124.64 126.60 128.55 130.51 132.46 134.42 136.37 138.33 140.28 142.24 144.19 146.15 148.10
4450 115.51 117.51 119.51 121.51 123.51 125.51 127.51 129.51 131.51 133.51 135.51 137.51 139.51 141.51 143.51 145.51 147.51 149.51 151.51
4550 118.10                                    
4650 120.70                                    
4750 123.30                                    
4850 125.89                                    
4950 128.49                                    
5050 131.08                                    

Last Updated on 11/8/99
By John Meister
Email: john@johnmeister.com/jeep/sj