I was doing some testing on my bike recently, it's a Bike-E recumbent like this.

**UNASSISTED:**

Normal riding position

Voltage: 24v

avg-speed: 13.5 mph

Rear tire: 40psi Knobby

Wh/mi: 15.5

Normal riding position

Voltage: 48v

avg speed: 12.5 mph

Rear tire: 100psi comet primo low rolling resistance tire

Wh/mi: 11.7 wh/mi

Draw legs close to the body, bring in head. (Curl up into a ball) [To minimize frontal area]

Voltage: 48v

avg speed: 12.5 mph

Rear tire: 100psi comet primo low rolling resistance tire

Wh/mi: 10.5 wh/mi

One time, I was trying to maximize my range because I had no idea how far my bike could go and my derailleur was busted so I couldn't pedal, so I went 10 mph and coasted wherever possible and minimized braking (To conserve energy).

Normal riding position

Voltage: 48v

avg speed: 10 mph

Rear tire: 100psi comet primo low rolling resistance tire

Wh/mi: 9.2 wh/mi

A neat way to figure out your watthours per mile, without relying on a CA to do it for you, is by dividing your power output by your speed.

So, this one time I was going 26 mph and my motor was consuming 450 watts, so my wh/mi at 26 mph was (450/26)=17.3 wh/mi. (I had my 40psi knobbies on at the time)

On my older upright bike like this:

It was consuming 770 watts to sustain 25.5 mph, so my wh/mi. was (770/25.5) = 30wh/mi which is a figure I remembered seeing on my CA.