CardHub.com has released its 2012 Credit Card Auto Rental Insurance Study, which compares coverage by the four major cards: Visa, Discover, MasterCard and American Express.

The study outlines coverage restrictions by card and type of vehicle, where it is rented, length of rental and nature of damage done to rental vehicle.

The study gave Visa the highest marks for its rental insurance coverage, followed by Discover, American Express and MasterCard. MasterCard is the only network that does not provide rental insurance coverage for all cardholders, the study reports.

In addition, none provides coverage for exotic, expensive or antique cars, or for off-road vehicles or those with open beds.

The study also found that:
• Accidents that occur on dirt roads aren't covered by Visa or MasterCard.

• Discover is the only card that provides coverage in all countries where Discover is accepted.

• Many popular full-size SUVs aren’t covered by American Express.

• Discover is the only network that does not exclude coverage in certain countries; none of the other three major networks covers rentals in at least Israel, Ireland, and Jamaica.

Click here for the full study.

The Auto Rental Summit, Oct. 29-30 at the Hollywood Beach Marriott in Hollywood, Fla., will present a seminar that examines credit card insurance coverage. The Auto Rental Summit is a gold-level training and education conference designed to improve customer service and revenues of car rental operations.