HP vs Torque vs Fuel Efficiency

[niky]

Pretty much.

I've finally got over my block.

The key is wheel speed.

As the speed of the wheel goes up, it covers a set distance in much less time.

Since F=MA, or F=MDist/Time, less time for the same distance equals less force.

Which fully agress with P=MAV.

[sendler]

There is another misconception about gearing that is related to energy. Motorcycle guys often change the final gear ratio by changing sprockets since it so easy and cheap to do. I went 15% longer for better fuel economy. Some guys go shorter for better acceleration and to get what they believe will be closer gear ratios. The interesting thing is that the rpm change between gears stays exactly the same either way. If you run 1st to redline at 10,500 and the rpm drops to 6,600 when you grab 2nd, that difference will remain the same regardless of what changes you make to the final drive. You would have to change the gear sets in the transmission to make the rpm drop to be closer between gears. But why do the gears FEEL closer with a lower final drive and FEEL so far apart with my long gearing when you are getting the same rpm drop as before? Because each shift point is now closer together in Energy with the shorter gearing.

[niky]

Or you could say it's also because the time interval has changed, even if the RPM interval has not.

[sendler]

A racer brought up a good point about going shorter on the final drive. You can make the rpm drop closer together by going shorter in the final drive. Throw away 6th by making it more like what 5th was. Make 5th into 4th, 4th into 3rd, ect. Now you are more often using one gear up from what you were using before, where most transmissions group the ratios closer together at the top.

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I cruise long distance on the highway so I use 6th (can't throw it away). And 7th (what was 6th before I went longer on my sprockets).