If your boss is picking up the tab for business travel, you might not pay too much attention to the number of miles you put on your rental car. It's a different matter if the money is coming out of your own pocket. Each rental company sets its own policies regarding how many miles come with a standard rental. If you exceed the maximum, you might get hit with a hefty additional fee.
Mileage Fees
Every mile you put on a rental car contributes to its depreciation in value, just as it does to your own car. Car rental companies take this fact into consideration, and build the value of that depreciation into the cost when setting their rental fees. Each company determines how it will recoup that cost, which could range from including unlimited mileage for a flat fee, or charging a per-mile-driven fee.
Contract
You always pay for mileage on a rental car. Whether that charge is part of the rental fee or billed as a surcharge depends on the contract. Some car rental companies offer you the option of choosing unlimited miles, typically for a higher rate, or of having a per-day mileage cap for a lower rate. Which type of contract is better depends on how you plan to use the car. If you expect to do limited driving -- for example, less than 150 miles per day -- you could save a few dollars a day by choosing a car with a mileage cap, according to the Thrifty website.
Unlimited Limitations
Unlimited mileage sounds great, especially if you're renting a car for a cross-country vacation and you don't want to be tethered to a mileage cap. But not all unlimited rates are created equal. Some car rental companies only allow unlimited mileage within the state, or in surrounding states. GPS tracking systems, common on rental cars, let the rental company know where the vehicle is. If you drive outside the permitted region, you could get a big, and unpleasant, surprise when you turn in your car.
Specialty Vehicles
If you rent a specialty vehicle, such as an SUV or a high-performance sports car, get ready to pay a premium rental rate. That goes for any additional mileage charge as well as the basic rental rate. Some rental companies apply different mileage caps on their fancy cars, so check your contract carefully before you drive off the lot to prevent unexpected excess mileage charges.
