Renting a car can be very convenient while you are traveling, but can also be costly as well. If you are looking to save money, then you may want to follow these few tips to help you:

1. Fill Up the Gas Before Returning the Car: If you leave the tank empty when you return the car, then the car rental company will charge you a large amount of money to have it filled. This isn't something you want to do because the rental company will charge you much more for the gas than you would otherwise pay at the local gas station. Sometimes, this won't be allowed. If this is the case, then just be sure that you waste as little gas as possible while using the car.
2. Don't Rent from Airport Rental Car Service: If possible, try not to rent a vehicle from the airport since the fees are usually much more costly. Yes, it is convenient, but if you can take a shuttle to a nearby rental company, then you may be saving more in the end on the price of the car rental. 
3. Don't Opt for Other Services: In the case that your car rental company tells you to get car rental insurance, try not to give in. This is usually a service that you will not need. This is because your own auto insurance will be able to cover everything you may need in the case of an accident and you will not need to use the rental insurance at all. Just be sure that you call your auto insurance company to confirm this. Your agent will let you know of all coverage that is provided to you with your car rental so you are not left in the dark as far as understanding what types of coverage that you have.
4. Ask for the Smallest Car: If you are traveling alone for business or are just traveling with one other person, then ask the rental company to reserve you the smallest car possible. This can save you a large amount of money, especially on the cost of gas. Besides, many rental companies only have a select few of smaller, compact vehicles. If the rental company is all out of these small cars when you arrive, then they will provide you with a larger one free of charge. 

By knowing how to save on your car rental, you can make your travel costs significantly lower, which can make your travel that much more stress free.