toruqe versus acceleration

[SaabJohan]

Torque is not a force, nor it is a force*distance. Torque is a moment, created by a force acting on a radius multiplied with sinus the angle between the vectors r and F.

A moment can be used to do work, this does however not mean that the moment is work; and if the moment is used to do work, power will be needed. Power is defined as work per time unit and work as a force multiplied with a distance (these are just one of many definitions).
Note that work can't be measured in horsepowers, but horsepower*hour or kWh is possible.

As one can see torque has the same unit as energy/work (N*m in SI units), this do not mean that they are related, becase they aren't. Torque is a vector while energy/work is scalar.

A car can like all bodies be accelerated by F=m*a. The force that accelerated the car is the sum of the torque*radius on all driven wheels, minus the force that is needed to sustain speed.

The force accelerating the car can be highest where the power is highest since most torque per time unit are produced there. However, on any given gear, the force will be highest at peak torque since the gearing will act as a constant torque multiplier.

So for engines power is what's important, torque as a number is not important but the torque curve (or power curve) is important since we can't run the engine on a constant speed (well, you can, but...).
We can for example create the same power using a high speed turbine as using a slow speed piston, the later will create the highest torque but not necessarily the best torque curve.

Also, if we talk piston engines for example; we can create a more powerful engine if we allow ourself to use a more narrow powerband. This is one of the reasons that racing engines are very powerful, but only under a limited rpm range.