Hi Susan,
If you are wanting to track multiple fuel types as a COGS item, I would suggest creating and treating them as consumable materials in the Pricebook (in HVAC, this might be how you track different refrigerants as well). You will then want to use the PO system to purchase and receive these different fuel types. Then, you will need to consume the fuel. You can do this automatically, by tying it to different tasks/services you provide, by adding it to an invoice in Mobile or Office, or by selecting the "Consume Item on Transfer to Truck" option when setting up your fuels as materials.
Typically, I've seen fuel costs monitored on the accounting side as a fleet cost and not tracked so granularly. Rather, it's allocated as a cost per department as a percentage of sales for example if you are creating departmentalized income statements or as a flat cost of doing business. Of course, I am making a few assumptions about your business and goals with this response.
Best,
Charles Wiercinski
