Originally Posted by

**Marlborofranz**
This is true, but isn't it the result more or less the same? Serious question... Because by looking for the point where you have the most horsepower, you also have the point for the highest torque. Because horsepower is just a value calculated from Torque and RPM. It's just another formula to find where the torque curves of the lower and higher gear start to intersect each other, which is the optimum shift point.

About torque: Yes it is simplified, but assuming you have two cars with a 150 HP diesel and a 150 HP gas engine, both can pull exactly the same mass. Of course, if you use the same gearing ratio for both cars, the diesel engine will pull more mass and accelerate quicker, but has less top speed due to the limited RPM range. But if you adjust the gearing ratio so both cars have the same speed at red line, then they will accelerate the same and pull the same mass. At different RPM's due to engine design, but they can pull exact the same mass.

You can have the exact same effect as when using two identical cars/engines but change the gearing ratio towards top speed and towards acceleration. You will just adjust the amount of torque vs RPM arriving at your wheels. But the engine will do the same. It doesn't make a difference about the horsepower because the horsepower is always the same. Torque and RPM = horsepower.

So when calculating the optimum shift point based on horsepower and the gearing ratio, it is the same as doing this based on torque and the gearing ratio. Both calculations provide the RPM at which to shift, which is the RPM at which the torque line of gear one intersects with the torque line of gear two.