If rented long enough oil changes could be required as well, especially if it is used in a 24/7 operation condition.That is the biggest concern by RV rental unit outlets because renters don't take care of the gensets. They thought that you just start the unit and keep adding fuel when they (gensets) ran out of gas.
RV Rental outlets require a deposit to cover expenses in case the genset requires repair when returned.
Generators are prone to damage when operated in dusty environment. It really needs replacement of filter every so many hours of operation.
The sand dust in the desert will choke everyone--almost.
This deposit is required when you attend the BURNING MAN.