I have mine on the drivers side. It is somewhat arbitrary unless you have specific non-moveable things that will go with it. I have a shelf I built that mounts on the side of my 110 under the awning, but I put that there after mounting the awning on the drivers side anyway, but now I'm committed to that side.
One thing I've learned to think from a sides standpoint with awnings is the following:
- Most people camp in good weather when it's warm
- In the morning, you want the sun under the awning for warmth during breakfast
- In the evening, you want the shade from the awning to escape the fleeting heat
With all those in mind, I make sure that when I am parking at a site to setup the awning for overnight, that I park facing South, so that the driver side awning is shaded at dusk, blocking the Western sunset with the vehicle and awning shade, and lit at dawn by the rising sun in the East with no obstructions.
If you mount on passenger side, that logic is opposite. In the fall and winter, you would only use an awning to shelter from precipitation, then it doesn't really matter.