Super duty 10 speed gear ratios
Very similar to the 1/2 ton ratios. They are probably all excellent but my personal preference is that they would have left reverse as a higher speed. I think it was 1:-3.4 in the 6 speed Super Dut...
Forum Discussion
Percent increase in RPM
by dropping from the next higher gear
First 4.615:1 58.10208976
Second 2.919:1 36.91369606
Third 2.132:1 20.24816695
Fourth 1.773:1 16.72152732
Fifth 1.519:1 23.79788101
Sixth 1.277:1 21.48514851
Seventh 1:01 18.82352941
Eigth 0.851:1 23.72634643
Ninth 0.687:1 8.702531646
Tenth 0.632:1
Yes, the 58% increase in RPM going from 2nd to first is much more noticeable than the 23% going from 9th to 8th. On the other hand, going from 10th to 9th is so small as to make one wonder why they bothered.
First gear is really low to minimize slippage and heat while getting the rig rolling or maneuvering. Once you are fast enough to get out of first you should be able to lock the clutches in 2nd and still have decent acceleration. The same with 2nd to 3rd gear. Going between gears from 3rd through 9th the changes are all in the 20% range so you should be able to keep the engine near full power at the speeds covered by these ranges. You are not likely to put full horsepower to the ground in either 1st or 2nd but as the gears climb and speed increases you are more and more likely to want full power for extended periods. Thus the closer gears in the higher ratios. I have no explanation for 9th and 10th being so close.
by dropping from the next higher gear
First 4.615:1 58.10208976
Second 2.919:1 36.91369606
Third 2.132:1 20.24816695
Fourth 1.773:1 16.72152732
Fifth 1.519:1 23.79788101
Sixth 1.277:1 21.48514851
Seventh 1:01 18.82352941
Eigth 0.851:1 23.72634643
Ninth 0.687:1 8.702531646
Tenth 0.632:1
Yes, the 58% increase in RPM going from 2nd to first is much more noticeable than the 23% going from 9th to 8th. On the other hand, going from 10th to 9th is so small as to make one wonder why they bothered.
First gear is really low to minimize slippage and heat while getting the rig rolling or maneuvering. Once you are fast enough to get out of first you should be able to lock the clutches in 2nd and still have decent acceleration. The same with 2nd to 3rd gear. Going between gears from 3rd through 9th the changes are all in the 20% range so you should be able to keep the engine near full power at the speeds covered by these ranges. You are not likely to put full horsepower to the ground in either 1st or 2nd but as the gears climb and speed increases you are more and more likely to want full power for extended periods. Thus the closer gears in the higher ratios. I have no explanation for 9th and 10th being so close.
