HP is good, torque is better, torque pulls you up
hills, and works better offroad, HP gets the speed
up after the low RPMs pick up and you get on the
highway.
SuperChargers, and TurboChargers help to increase
both torque and HP by force feeding the engine more
fuel and air, basicly makes a small engine act like a
bigger one.
Gears will increase your available torque without changing
the engine, but you will loose high speed, over 60 MPH
to too many RPM, tho these little engines are quite happy
at 4,000 to 4,500 revs.