4 spd vs 5 spd pros and cons

[BAD ASP]

I went with the viper t-56 6spd..... as one of your earlier replies shows on a 5 speed this car with its 6th gear will be turning 1500 rpm @ 54 mph and 2000 @ 74 so at highway speeds it is as economical as it gets and extends the range on these small gas tanks. I also notice that the gear transitions are smoother.... my wife appreciated that as a passenger. Purists will have their say and I toyed with things as well...... the viper tranny is rated to 800 hp. so it is robust enough for almost all of our applications... here is the gear calc.... i have 565 rwhp on a mustang dyno....

Gear 1st 2nd 3rd 4th 5th 6th
Trans Ratio 2.66 1.78 1.30 1.00 0.79 0.63
Overall Ratio 9.44 6.32 4.62 3.55 2.80 2.24
Split 1.49 1.37 1.30 1.27 1.25
Rev/Mile 6,845 4,581 3,345 2,573 2,033 1,621
1500 13 20 27 35 44 56
2000 18 26 36 47 59 74
2500 22 33 45 58 74 93
3000 26 39 54 70 89 111
3500 31 46 63 82 103 130
4000 35 52 72 93 118 148
4500 39 59 81 105 133 167
5000 44 65 90 117 148 185
5500 48 72 99 128 162 204
6000 53 79 108 140 177 222
6500 57 85 117 152 192 241
7000 61 92 126 163 207 259