Tracking Mileages for Fleet

Pebbles38 

Is there anything to make it read the interval so I don’t have to manually change the due? ...

I actually have a larger spreadsheet  with other data to add in this is just testing it out for function. 

I can answer the first question --is there anything to make it read the interval--with a resounding "Yes!" But that won't really help you much until you explain what you mean more fully. Why don't you save us all a lot of back and forth and give us the bigger picture at the start. 

For example, that 5,000 mile interval is for oil changes. Are there other (there are, I know from my own automobile service manual) intervals for other forms of service? And is it all of those intervals that need to be read--not just the 5K for oil? For example, intervals for tire rotation; wiper changes; battery replacement; anti-freeze changed....etc.  Do the intervals stay the same for different vehicles, or would you need to have different intervals based on the brand or type of vehicle?

The reality is that it would be fairly simple to create a table which could be used to lookup the appropriate interval for any given vehicle for any type of service.

Here's a resource that would help you devise your own lookup capabilities, if that is something you'd enjoy doing. If you'd like more help here, come back with a more complete description of the task, and if you have that larger spreadsheet and are willing to share it, put a copy on OneDrive or GoogleDrive and paste a link here that grants access to it.