Originally Posted by Ziggyrama
You would not want your car to make constant torque value across entire rpm range. You do not need max power all the time. Energy that would not be turned into kinetic energy would have to be dissipated another way, as in heat. You'd end up with 5mpg economy and a giant ball of heat that would likely destroy the car in short order.
If by that you mean at all throttle positions, then of course. The whole point of a throttle (in the physical sense) is that it drastically affects the VE curve of the engine for that particular RPM and thus changes the load. But flat torque at full throttle from say 2500RPM to redline? That would be the holy grail of engine tuning.
As an example, here's a dynograph of a stock Honda S2000:
Besides the bump at around 6250RPM when VTECH kicks in, it's pretty much a flat torque curve.
Now turbocharged cars are pretty much never going to do that unless you intentionally don't max it out in the lower RPM's. But I was simply using that to illustrate my point about what load represents. If you want to see a turbo car that comes close, here's a 2012 GTR:
It's basically flat from 3500-5250, and I bet if you looked at the engine map there is a constant load between those two points.