Using named ranges to sum up values throughout a worksheet?

I have a workbook that has information on vehicles. Each vehicle has its own row, and the A column includes a serial number for each vehicle. Columns G and H have values for each vehicle (gallons and mileage) that I want to sum up.

I have organized all the serial numbers that appear in the workbook into a series of named ranges. Each named range is basically a group of vehicles, organized by serial number. For each sheet, I hope to get the total gallons (G column) and mileage (H column) associated with each named range. 

I need two formulas:

1) One that, for each named range, locates every cell in the A column that contains one of the range's values, then sums up all the corresponding (on the same row) cells in the G column. 

1) One that does the same, but sums up corresponding values in the H column. 

Let me know if you can help me with this. I can attach the workbook if needed.