Deslock

For similar conditions, that's true (increased wheel force results in increased acceleration). But what you wrote doesn't necessarily apply to different speeds. Air drag increases as a square function of speed and more of the wheel torque is needed to offset it at higher speeds. As a result, less of the car's wheel torque is available to accelerate at higher speeds (so it's possible that wheel torque could increase as the RPMs climb, but not enough to offset the increased air drag, resulting in less acceleration).

Of course, in the context of torque vs power, none of that really matters.
True, but that's the same thing as saying wheel torque is proportional to engine power (at any wheel/vehicle speed). Writing it the way you did in a torque vs power discussion may have been part of the reason some people got so confused.

Also true, but in the context of this discussion, it should be mentioned that the precision of an engine's output is not significantly different whether you're looking at peak engine power or peak engine torque. Again, I could see people getting confused by what you wrote.

We don't feel engine torque directly either. We feel the force of the seat pushing us forward, which comes from the force at the wheels, which comes from whatever wheel torque is not being used to offset the road grade, air resistance, etc. Also, wheel torque is proportional to EnginePower / Speed or EngineTorque * Gearing, depending on how you want to calculate it.

I understand what you're getting at, but power is just a measurement of how quickly you can apply a force (power = force * velocity). If that force is applied directionally, so is the power.

globi

Actually I wrote it like that because many people mix up engine power with maximum power. In that case you should really say wheel torque is proportional to engine power at that engine speed and wheel speed.

What I mean is that you can feel the torque when you touch an axle or you can feel a force when you get pushed by something. But we humans don't really have any 'sensors' that can feel work or power directly.

It's true that power can have a direction (although this is not how it's usually determined or measured at least not when you look at an engine), but even then we humans have difficulties feeling it. It would mean that we can feel speed at any given acceleration, which we have a hard time with since we can't really measure speed (our eyes and ears are not very accurate speedometers).

globi

Deslock, I have to give you credit. Your torque power post was the best I've read so far. (Unfortunately I didn't read it before I posted mine).