One of the Chase Sapphire card's most overlooked benefits is also one of its most valuable

Business Insider may receive a commission from The Points Guy Affiliate Network if you apply for a credit card, but our reporting and recommendations are always independent and objective.The Chase Sapphire Reserve credit card comes with free primary rental car insurance.As long as you use the card to pay for the rental, you'll be covered for any loss or damage to the car.You'll also earn 3x points per dollar spent on the rental.The Chase Sapphire Reserve is a phenomenal all-around credit card, but one of its most forgotten features is also among its most valuable — especially if you ever rent cars.Rental cars are often a necessity when you travel, assuming that you're looking to get anywhere off the beaten path or out of the city, where public transit may be more limited.While rental car costs can add up — between gas and taxes and fees — the Sapphire Reserve (and its sister, the Chase Sapphire Preferred Card) comes with primary rental car insurance, meaning you can save money on the rental agency's collision/loss damage waiver and accident coverage. Here's how it works.The thing that makes the Sapphire Reserve's rental insurance so useful is that it's primaryWhen rental car insurance is primary, it means that it applies before your main personal insurance policy, and covers full damages or loss due to collisions or theft. That means you won't have to file a claim with your own insurance, so you won't have to pay a deductible or potentially see your rates increase.Secondary coverage, on the other hand, takes effect after your personal insurance. It often has a deductible, and may not cover the full cost of the repair or replacement. Of course, if you don't have personal car insurance (because you don't have a car), most secondary coverage becomes primary.The free auto rental collision damage waiver covers up to $75,000 of coverage for damage or loss in the event of theft or collisions, and it applies both in the US and abroad. Both the cardholder and any authorized drivers listed on the rental are covered.In order to take advantage of the primary rental car insurance that comes with your Sapphire Preferred or Reserve, simply decline the “collision damage waiver” or “loss damage waiver” offered by the rental agency, and pay with your Sapphire card instead.Keep in mind, though, that the Chase insurance doesn't include liability coverage,. If your personal auto insurance includes liability coverage, you're all set, but if you don't have auto insurance otherwise, you should consider purchasing that from the rental agency. I live in New York City and don't own a car, so I don't have auto insurance — whenever I rent a car, I decline the collision/loss coverage, but always purchase liability insurance to be on the safe side.You can get a few other savings and benefits, tooHaving the Chase Sapphire Reserve entitles you to a special privileges with a few major car rental agencies.At National Car Rental, you can get complimentary Executive level elite status in the agency's loyalty program, Executive Club. That gets you an upgraded car type, faster rentals, a better choice of cars, waived fees to add a second driver to your account, and more. You can also get a discount of up to 25% when you book directly, pay with the Sapphire Reserve, and use the discount code 5030849.You can also get benefits with Avis by activating complimentary Avis Preferred membership (although this is available even if you don't have the Sapphire Reserve). That entitles you to Avis Preferred Service, up to 50% more rewards points on rentals, and complementary upgrades where available. You can also get discounts of up to 30% with the code S107100 when you pay with the card.Finally, Sapphire Reserve cardholders can get benefits with Silvercar — primarily, a 30% discount.To activate these deals, log into your Chase account, and visit the Sapphire Reserve's Card Benefits page.Click here to learn more about the Chase Sapphire Reserve from Business Insider's partner: The Points Guy.