gasoline engines have a horsepower "bell curve", and you know how manufacturers are...they advertise PEAK HP.
Gasoline engines really dont have a continuous RPM/load "setting" and then a peak temporary load. Motors are like that. You normally buy the smallest cheapest e-motor that can do the job at a continuous RPM at a specific voltage. That being said we can all overvolt motors a little as long as we dont over-load them too much or for too long a time, then they gain more heat than they can shed.
An electric motor has better efficiency at higher RPM's, but as far as power goes, they have most of it available from a standing start. If you can vary armature current (as some are experimenting with) you can use only the current needed. More at the start, and less as speed increases and stabilises. The simplest common motors dont vary armature current, so they get hot under heavy loads such as standing start accelleration, and then they are wasteful of Watts when just cruising.
If motors were dirt cheap and batteries were horribly expensive, there would be more creativity with motors. Fortunately the selection is improving for everyone recently. I'm no expert, but I've read of some of the ways to have max design accelleration power and also "watt-sipping" cruise are: two free-wheeling motors. Both used for accel, and one used for cruise, then, motor/voltage selected for max loads, but armature current is adjustable to only whats needed at that moment, also, Delta/Wye switching, also sacrificing raw accelleration and hill-climbing speed by using a smaller motor, but running it through a 3-speed trike hub as a transmission.
Another idea with the wide RPM range available with the recent RC motor experiments might be voltage switching. Perhaps 48V for acceleration, then 24V for range? (don't know if that would work or not...)
My 18-wheeler only has about 500 HP, but I have 14 gears and accellerate slowly, so I get 7 MPG when hauling 80,000 lbs. (40 tons) Can you imagine a 100 HP economy car hauling 16,000 lbs (8 tons)