I've tried to attach a sample, but it won't allow it. The first sheet in the workbook has "Date" "Vehicle Number" "Driver" "Mileage" "Gallons Purchased".

The second sheet has "Date" "Vehicle Number" "Driver" "Mileage".

The final sheet should have all of these columns merged in such a way that you can tell the vehicles MPG rating versus miles driven.

When I've tried to combine these sheets, I can only merge the rows - I cannot get them to match the dates with the vehicles and then the gallons purchased with the mileage listed for that vehicle on the specific day.

I know without a visual representation, it's difficult. but, if you set up a workbook with the column headers I mentioned, you should be able to figure it out - I hope :)

Thanks