Relationship between the transmission ratio and the vehicle speed and torque

Remember when in University, a small series of two teachers often is a topic of much bukekaijiao, who cannot persuade afford much food for thought, that the topic is " what on earth as a shifting basis ". A teacher should be speed is accurate, his many years of driving experience " a stop Cable for Renault Can Clip~ start immediately, change into two gear, thirty kilometers above hanging block three, more than forty kilometers into the four block" is a practice that truth, can do no wrong; another teacher insists that the principle of the supremacy of speed, low gear complex to two thousand rpm, high speed three thousand to four thousand gear change ". Small make up their own natural not qualified to comment on which teachers say to themselves, but learned a bit of theory and data table, you want to help readers to judge. Who is right and who is wrong, that the different people, different views.
First of all, try on this topic, must be on the drive ratio, power, torque, speed, speed is a concept only row ( described below theory and derivation process of implicit ignoring resistance and mechanical efficiency of 1 the ideal condition, the unit used for the international unit ). The transmission ratio is defined as the speed of the driving gear and the driven wheel speed ratio. In the car, the total transmission ratio is equal to the speed of the engine and the driving wheel speed, is equal to the driving wheel torque / torque of the engine, more equal to the transmission ratio * main reducer transmission ratio ( commonly known as the final transmission ratio ). Power per unit time, the working value. Automobile engine power is equal to the engine torque engine speed /9550 *, according to the transmission ratio of transformation, also can be equal to the driving wheel torque drive wheel speed. Torque, physics explanation for torque, equal to the force * arm ( because the force is proportional to acceleration, so the torque and angular acceleration is proportional ), is a measure of the object rotational angular acceleration size parameters. Speed, is the speed of vehicles. Speed two, a rotation speed of the engine, the driving wheel speed. The business is overall gear ratio, the premise is the driving wheel in the attachment of good roads, without slipping or locking phenomenon. The driving wheel speed and speed conversion relation is: speed = driving wheel speed *60*2 π* driving wheel radius /1000.
Believe many readers will be those annoying formula to get dizzy, don't worry, understanding of the process of how the lack of examples? Below small make up examples let us try to understand. Saying that there is A, B two cars, in addition to the engine parameters are different, the rest are all the same, where the drive wheel radius is 0.5m. Two car torque curve as follows:

Figure: A car's torque curve 6000 turn off the oil, peak torque and peak power at 3000 rpm. Peak torque is 300 Nm, the peak power of 90Kw