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4.09 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 4.09

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Gears: 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09 4.09
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 12.60 12.82 13.04 13.26 13.48 13.70 13.91 14.13 14.35 14.57 14.79 15.00 15.22 15.44 15.66 15.88 16.10 16.31 16.53
700 14.70 14.96 15.21 15.47 15.72 15.98 16.23 16.49 16.74 17.00 17.25 17.51 17.76 18.01 18.27 18.52 18.78 19.03 19.29
800 16.81 17.10 17.39 17.68 17.97 18.26 18.55 18.84 19.13 19.42 19.71 20.01 20.30 20.59 20.88 21.17 21.46 21.75 22.04
900 18.91 19.23 19.56 19.89 20.22 20.54 20.87 21.20 21.52 21.85 22.18 22.51 22.83 23.16 23.49 23.82 24.14 24.47 24.80
1000 21.01 21.37 21.73 22.10 22.46 22.83 23.19 23.55 23.92 24.28 24.64 25.01 25.37 25.73 26.10 26.46 26.83 27.19 27.55
1100 23.11 23.51 23.91 24.31 24.71 25.11 25.51 25.91 26.31 26.71 27.11 27.51 27.91 28.31 28.71 29.11 29.51 29.91 30.31
1200 25.21 25.64 26.08 26.52 26.95 27.39 27.83 28.26 28.70 29.14 29.57 30.01 30.45 30.88 31.32 31.75 32.19 32.63 33.06
1300 27.31 27.78 28.25 28.73 29.20 29.67 30.15 30.62 31.09 31.56 32.04 32.51 32.98 33.46 33.93 34.40 34.87 35.35 35.82
1400 29.41 29.92 30.43 30.94 31.45 31.96 32.46 32.97 33.48 33.99 34.50 35.01 35.52 36.03 36.54 37.05 37.56 38.07 38.57
1500 31.51 32.06 32.60 33.15 33.69 34.24 34.78 35.33 35.87 36.42</