On a flight last summer on a particularly hot day in Atlanta I noticed all the fuel was being consumed mostly from the LEFT TANK. When entering the pattern at my destination I noticed there was no fuel available at this small mountain airport. I made a beeline to my alternate and upon arrival I was down to 3 gallons in the left tank. I found this very concerning.
One of the nice features of the Dynon Avionics is that it saves many of the flight parameters to a "black box" file. You can download it to an USB thumb drive and then graph the data on a PC later.
Here you can see the Left Tank is draining at the same rate as the engine fuel burn: 6 gal/hour.
Vashon maintains a fuel imbalance is perfectly normal for a high wing aircraft that is not equipped with a fuel selector valve. They have only experienced this in one other Ranger. However, they attributed that to the fact it was doing touch and goes and was constantly making left hand turns only.
It should be noted that each of the main tanks drains into a 2.5 gal header tank via gravity. The engine driven fuel pump and the electric driven fuel pump then pulls fuel from the header tank and not the main tanks.
I my opinion this was caused by fuel vapor lock in the hot Atlanta sun. The fuel line runs down the inside of the cabin along a structural member and is wrapped in a black fabric. I made a stand off and wrapped both fuel lines in special Fuel Line Vapor Lock Insulation from Summit Racing. The problem has not occurred again.