That question is best directed at the C/Card company, as they can give you a definite answer. You should be ask to email it to them.

Be prepared to get a car with a nearly bone-dry gas tank. You'll be told that you can 'bring it back empty'. There is a gas station just outside of the airport access road before turning towards Amman. Whatever leftover gas you leave in the tank will be siphoned out by the rental car employees for their own use or sale, leaving just enough for the next person to make a bee-line for the fuel station. (To be fair, this is not specific to Jordan, but be advised that it does occur and you will need gasoline almost immediately).