And I'm not sure why..
I was riding home, at Interestate speeds of 70-75mph, into the wind, and I ended up having to switch to reserve at 189 miles on the tank.. I rode to the next exit and filled it back up and only put in 4.8 gallons..
Seemed kinda odd that it needed to be switched to reserve at 4.8 gallons..
The simple explaination is that the remainder of your fuel was stuck in the back half
of your tank due to a centripital-induced, temprature retarded, force.
The accelleration and subquent high sustained speeds caused the fuel in your tank to be
semi-permanantly retained in the aft or rearmost portion of your fuel tank. Normally the
fuel would have sloshed ("Sloshed is a technical term for splashed) back to the center
of the tank but the high speeds you experienced created a vaccum, or low pressure area,
on the bottom center of the tank.
This low pressure area is a result of the Venturi effect, the low pressure area cooled the
tank to a tempreature below or nearly below the "Gel" temp of the fuel.
When you re-fueled the tank the cold fuel warmed up and settled back to the middle
of the tank and your quantity was seemingly off.