How to record inventory when used internally

I'll guide you in handling that, Ibefunk.

You can combine inventory parts in QuickBooks Desktop to build and track the finished goods that you sell. Based on your example, you can set up the tires as inventory parts if you track their quantity. If you don’t track them, use non-inventory parts. For components that involve charges and fees when building, you'll have to set them up as other charge items. 

After that, add the bill of materials using an inventory assembly item. Once you're ready to combine or assemble the items, just follow the steps below:

1. Go to the Inventory menu, then select Build Assemblies.
2. If you don't see this menu, go to Vendors and select Inventory Activities>Build Assemblies.
3. Select the product you want to build from the Assembly Item drop-down menu.
4. Review the quantity on hand, quantity needed, and other information.
5. Enter the quantity needed to assemble the final product.
6. Add a memo as needed, then click Save and Close.

To learn more about how to set up items you assemble using components, you can read this article: Track the products you manufacture.

If you have any other inventory management questions, feel free to leave them below. I"ll get back to you as soon as I can.