There is a nice graphic here:

https://www.tripsavvy.com/types-of-motorhomes-2912600

Basically, you have to determine the business use, reason for the vehicle, or it is treated as real estate. Examples:

Site Office (construction site, sales on site, etc)

Air BnB (rental income)

Drive it to rallies as a vendor

Used for personal camping (primary residence, second home) and if personal use, was it taxed as a fringe benefit?

https://www.irs.gov/taxtopics/tc415

That's why %s matter

If mixed use, then mileage matters.

Everything matters. It's not unusual to have a taxpayer who believes putting it in the name of the company turns it into a business asset. There is a story on the web for an RV registered under a business name, and reported on business taxes, which voided the warranty.