Questions about kw, hp and torque

[craigvk]

Just curious about power of vehicles. My car boasts 117kw at 4 or so thousand revs. My brothers Astra is 91 or so kw. What makes a car more powerful? Is it horse power or kilowatt? I am trying to figure out what makes a car more powerful.

In reality, how much more powerful is my 5L Calais compared to a 91kw Astra?

Thanks.

 

[jules]

hP and kW are different units of power, they refer to the same thing. it's like inches and cm.

the old V8s weren't that powerful so it's probably not a whole heap more than your astra and perhaps not really much faster if you factor in the mass advantage of the astra

 

[Stewart1000]

yeah, something like 1kw = 1.33hp... something like that i think.
torque is pulling power. i looked this up to help explain torque, hp is how fast you can supply the torque (sort of)...
For an extreme example of this, I'll leave carland for a moment, and describe a waterwheel I got to watch awhile ago. This was a pretty massive wheel (built a couple of hundred years ago), rotating lazily on a shaft which was connected to the works inside a flour mill. Working some things out from what the people in the mill said, I was able to determine that the wheel typically generated about 2600(!) foot pounds of torque. I had clocked its speed, and determined that it was rotating at about 12 rpm. If we hooked that wheel to, say, the drivewheels of a car, that car would go from zero to twelve rpm in a flash, and the waterwheel would hardly notice .