Always remember to mark if a fuel-up is a "Partial" or "Missed" if you misplaced your last receipt.
 

All fuel-up information from the second fuel-up should be added in MyGauges: gallons added, cost per gallon, average gvw, average speed, outside temp, any trip notes that might be useful when reviewing your mileage at a later time like head wind, mountain pass, etc. There is also a place to mark the location of the fuel-up and even review the truck stop.
 

To rate and review a truck stop you would click on the gray bar just above the submit button, named "Rate and review this location".
 

Note: The more accurate information you add the better your results when reviewing your fuel mileage