If you’re required to have an ELD, it doesn’t matter which vehicle you’re driving, according to Joe DeLorenzo, head of enforcement and compliance at the Federal Motor Carrier Safety Administration (FMCSA).
If you use a rented vehicle with an ELD system, make sure you have the current day and previous 7 days of logs on-hand for inspections. You can show the safety officer your phone or tablet if that's what you usually use for logging Hours of Service, or you can print out the records beforehand.
Keep in mind that under the ELD rule, commercial drivers are required to keep an ELD manual and data transfer instruction sheet on-hand. So make sure you have the proper documentation in the rental.
There is a limited exemption for carriers that use a rented CMV for eight days or less. In this scenario, you aren’t required to use an ELD, regardless of what the vehicle is being used for. Check out the Federal Register for more details about this exemption.