Assuming you own these trucks and the tires used are standardized, log the trucks as assets and any tires not installed on trucks in the parts inventory. Label the storage racks or label holders instead of the tires themselves. Log any tire rotations or replacements via work orders, adding the appropriate part to the work order to be consumed upon completion. Use a custom category for these types of jobs so you can filter them later. Standardize the title or a procedure field with a custom ID to indicate which wheel is being worked on.

Once you have this data flow going, it should be much easier to track down your tires. 

I do not know if there is a good way to do this. Unfortunately, in the trucking industry, tires are one of those things that are very hard to “plan” for. Road debris and hot pavement are not kind to rubber. Having said that, I track tires on a spreadsheet. I have each unit listed and then a column for each tire position. I record the date the tire was replaced, the reason it was replaced and the mileage at the time of replacement. It can be a little time consuming to do it this way but it is the best way I have found to do it.