Sound loop

im taking a look at the sound class for the first time. With something like a driving truck, how would you best simulate the looping engine sound during acceleration /deceleration? one steady sound looping is not realistic as speed changes

some thoughts i had:
-raise volume based on speed/torque?
or
-set of a few different sounds to change to as it gets higher, (slow, med, high, very high). perhaps if they are similar enough, they will blend as your car accelerates, looping the appropriate sound to match the speed.

also while im asking, is it best practice to keep soundChannels separate only when needed? example jump, fall,crash… those should never play simultaneous , so should i use the same channel for them, but keep a separate channel for sound effects in the background.

thanks you