Car rental companies often offer travelers a wide range of vehicle models.  What most customers don’t need are a lot of the extra, pricey services or the unexpected gotchas that appear on your bill when you bring back the vehicle. 

Here are some money-saving tips from Consumer Reports:

• Treat a rental car like a hotel mini bar.  Don’t take any “goodies” without knowing the prices.  This includes things like GPS navigation, satellite radio and child safety seats.

• Think twice before signing up for the “full gas tank” option where they refill the tank for you when you bring the car back … at their gas price.  Sometimes it’s as much as $8/gallon.  The convenience of not having to return the car with a full tank could cost you big time.

• Don’t rent more car than you need.  Before you decide to take advantage of a special upgrade to a bigger vehicle, think about the impact on gas mileage.  Do you really need a bigger car, minivan or SUV and do you really want to pay for the extra gas it may use? 

• Travel with only what you need, not a lot of extras that add weight.  Every 100 pounds of weight reduces gas mileage by around 2%.  Also avoid carrying anything on the top of your vehicle.  It creates mileage-reducing drag. 

• Don't accept a loss damage waiver unless you need to. Car rental agents typically offer a loss damage waiver, but you may not need it if your own auto insurance policy includes collision and/or comprehensive coverage.  Or if you use a credit card that provides protection.  Call your insurer and credit card customer service before you hit the car rental desk to make sure.  It can save you money.

• Always pay by credit card so any inaccurate changes can be disputed.  

Planning to rent a car for your summer vacation?  Union families may save up to 25% on car rentals here.  If you pay online when reserving with the "pay now" feature, you can get additional discounts.   And enter to win 1 of 4 week-long car rentals here.

Want more consumer advice and money-saving tips?  Use your Union Plus discount to save 27% off Consumer Reports Online.  You’re also supporting a unionized company.