Owning a car without warranty protection can be unnerving. The uncertainty about breakdowns and surprise repair bills can take away the enjoyment of having an automobile and be a distraction from everything else that’s going on in life. Choosing an extended warranty adds peace of mind and lessens concerns, but this is only half the equation. You also need to decide on the warranty provider.

Keep reading as we explore two options: Endurance Warranty and Cornerstone United.  We’ll see how these two companies stack up by examining their approaches to customer service, claims processing, extended warranty plans, benefits, and openness. Reviewing this information will enable you to make a fully informed decision about coverage for your used car.

What Is an Extended Warranty?

The term “extended warranty” is commonly used in the industry to describe a type of automobile coverage available after the original manufacturer’s warranty (or factory warranty) has expired. You’ll come across other phrases, like “vehicle service contract” or “auto protection plan.”

These terms are often used interchangeably with an extended warranty or extended car warranty, and all mean the same thing. Of course, what’s protected by an extended warranty is determined by the coverage purchased and the company servicing the agreement.

Who Has the Best Extended Car Warranty? Let’s Compare

Comparing Endurance and Cornerstone is a match-up between veteran companies that take different approaches to the extended warranty business. Endurance has been in the extended warranty business since 2006. Through its Illinois headquarters, the company has paid hundreds of millions in customer claims since 2012. Beyond protecting thousands of vehicles, Endurance enjoys broad recognition for other accomplishments, too.

In 2023, Endurance was recognized as the “Best Vehicle Service Contract Provider” by The Business Concept. The same year, Endurance earned a place on the Inc. 5000 list and was named a “Top Place to Work” by the Chicago Tribune. In 2024, Endurance also received a “Top Workplaces” designation from USA Today.

In addition, Endurance is actively telling its story on social media. Visit Instagram, Facebook, and other platforms, and you’ll find hundreds of posts and thousands of followers highlighting what Endurance offers in terms of auto protection plans.

Meanwhile, Hickory, North Carolina-based Cornerstone United, has been offering extended warranties since 1973. Unlike Endurance’s direct-to-consumer method, Cornerstone United only sells its services through automotive retailers. If you’ve ever purchased a car through a dealership and been offered an extended warranty, tire and wheel protection package, dent protection plan, or a similar program, you may have already been exposed to what Cornerstone sells.

Adding an intermediary, a dealership, to the purchasing process makes it harder to determine the customer experience with Cornerstone. Buyers who had a positive encounter with a dealer will likely say good things about getting Cornerstone coverage. Conversely, a negative dealer experience isn’t likely to cast a Cornerstone extended warranty in a good light.

Cornerstone United isn’t active on social media, but its few posts target car dealers, not the users of its warranty services. That’s not surprising, given the company’s customers are auto retailers who resell Cornerstone extended warranties.

Coverage Options: What Plans Are Offered?

Most extended warranties are divided into stated component coverage and exclusionary plans. A stated component option means that parts not specified in the service contract are excluded from coverage. Different levels of coverage can expand the list of protected components. Stated component plans are more affordable because the covered parts list is defined, limiting possible costs to the warranty company.

Exclusionary coverage plans are similar to new car bumper-to-bumper warranties because they have few exceptions or exclusions. If something isn’t explicitly excluded (like brake pads, tires, and wiper blades), then it’s covered. This broad-ranging protection means higher premiums.

Endurance offers both kinds of vehicle protection plans, enabling car owners to balance coverage and budget protections. The company also uniquely offers mechanical breakdown insurance (MBI) to California drivers, something Cornerstone does not.

ENDURANCE	Coverage Type	Summary
Secure	Stated Component	Essential powertrain protection (engine, transmission, and drive axles)
Secure Plus	Stated Component	Powertrain protection with coverage for major components (brake, air conditioning, steering, and core electrical parts)
Superior	Stated Component	Highest level of stated component coverage, including protection for additional electrical components, the fuel system, the cooling system, and the front and rear suspension.
Select Premier	Stated Component	Protection for high-mileage vehicles (up to 150,000 miles), including coverage for the powertrain, electrical system, air conditioning, cooling system, fuel system, and premium electric parts (like power window motors or electronic door lock actuators).
Advantage	Stated Component	Stated component coverage combined with maintenance coverage worth up to $3,500.
Supreme	Exclusionary	Coverage for almost all vehicle components except as detailed in the contract. Protection similar to a factory bumper-to-bumper warranty
Supreme for Highline	Exclusionary	A unique exclusionary plan for select luxury models

Cornerstone offers numerous plan options tailored to the types of vehicles the dealer sells (new versus used). Depending on who you buy from and what cars they’re selling, you may be offered a stated component coverage plan (Xtra Series).

CORNERSTONE UNITED: Xtra Series	Coverage Type	Summary
X1/Powertrain	Stated Component	Core protection for the engine, transmission, and drive axle.
X2/Powertrain Plus	Stated Component	Powertrain protection and coverage for the cooling and fuel delivery system.
X3/Basic Coverage	Stated Component	Adds steering and suspension protection to the X2 plan.
X4/Comprehensive Coverage	Stated Component	Adds air conditioning, electrical, and brakes to the X3 plan.

Some dealers may also carry Cornerstone plans with both coverage options (Xpanded Series).

CORNERSTONE UNITED: Xpanded Series	Coverage Type	Summary
XP1/Bronze	Stated Component	Core protection for the engine, transmission, and drive axle.
XP2/Silver	Stated Component	Powertrain protection and coverage for the steering and basic electrical system.
XP3/Gold	Stated Component	The XP2 plan and expanded component list for the engine, steering, and electrical system.
XP4/Platinum	Stated Component	The XP3 plan and expanded component list for the suspension, engineering, brakes, and cooling system. Coverage for electronics and emissions.
Ultimate	Exclusionary	Coverage for almost all vehicle components except as detailed in the contract.

Customer Service Comparison

The key to a successful extended warranty experience is the provider’s customer service. A smooth encounter during the sign-up process includes getting help with a plan that meets your budget needs and coverage requirements.

Purchasing a vehicle service contract through Endurance is focused on one thing: finding a protection plan customized to your needs and budget. Accomplishing this task at a car dealer usually includes other financial steps, like finalizing the price of the car, hammering out financing, and dealing with a trade-in. A lot is going on, which can result in overpaying or getting too little or too much coverage.

Customer service is especially vital when there’s a claim. Both companies have a similar overall approach to submitting an extended warranty claim, with a few notable differences. The process begins with taking your car to a licensed repair facility, submitting a claim, and letting the warranty company, Endurance or Cornerstone, start the authorization process.

With Endurance, repair shops can file a claim by telephone or through a convenient online portal. Cornerstone also requires the repair shop, not the car owner, to submit the claim. In the next section, Claims Processing, we’ll cover these options in more detail.

Endurance’s multipoint approach to customer service is backed up by a track record of putting clients first. The company has regularly received the Stevie Award, a leading business awards program that recognizes outstanding companies and their customer service departments. In 2024, Endurance was awarded a Silver and a Bronze Stevie for its exceptional sales and customer service efforts, respectively.

Cornerstone lacks any third-party validation of the quality of its treatment of prospective customers and existing clients.

How Is the Claims Processing?

Submitting a repair claim through an extended warranty provider should be simple and direct. After all, the sooner covered repairs begin, the quicker you’re back on the road. Endurance customers just have to have the licensed repair shop of their choice call to start a claim (224-326-0619). However, Cornerstone customers are divided into two groups, each with a separate claims number and process. This split process can be confusing, especially for a car owner making a first-time claim with Cornerstone.

Endurance repair claims may require a $0 to $200 deductible to be paid before work can begin, but that will depend on your specific plan. Cornerstone is unclear on its deductible amounts.

The Endurance Mobile app makes claims follow-up incredibly convenient for customers. The app notifies you if there is an update on your claim, such as if an inspector is required to assess the repairs, a common step in the extended warranty industry if the work is complex. This ensures that repair shops don’t take shortcuts at the vehicle owner’s expense.

Endurance and Cornerstone customers can take their vehicles to any licensed repair facility for covered work. This capability means you can use a neighborhood mechanic or dealership service department. In truth, this is how many reputable extended warranty companies do business. If the shop is licensed to perform automotive repairs, it can be used for authorized work.

However, Endurance goes further by teaming with RepairPal to provide access to a network of over 2,800 certified service centers. This makes finding professional technicians a breeze. RepairPal-certified shops must meet strict customer service requirements and pass specific skill standards. In addition, all work performed by a RepairPal Partner Network shop is warrantied for at least 12 months or 12,000 miles.

Finding a RepairPal certified facility is as easy as searching online or contacting Endurance customer service for personalized help. Access to RepairPal’s Car Genius service, which offers expert advice from highly qualified technicians, is also included.

In contrast, Cornerstone doesn’t offer any repair shop referrals. The company doesn’t say why it takes this approach. Still, it’s reasonable to think that the seller of a Cornerstone extended warranty would want customers to return to their service department.

Other Benefits and Perks

Extended warranty companies that offer additional benefits can help reduce the stress associated with breakdowns and car repairs. Endurance and Cornerstone provide 24/7 roadside assistance, which includes towing, jump-starts, and other services. In addition, both companies also offer rental car reimbursement and trip interruption coverage.

Endurance customers also get perks that are unavailable from Cornerstone:

• Endurance Smartphone App: The Endurance app streamlines accessing customer service and the claims process. In addition, the app provides you access to your contract to contact your roadside assistance provider. So there’s no fumbling for phone numbers or account information. Endurance customers can also find plan details through the app.
• Endurance Elite Benefits: Endurance plan holders can access a free year of Elite Benefits. Just pay a small activation fee for up to $2,000 in value services, including tire repairs and replacements (up to four tires per year due to road hazards), key fob replacement, collision repair discounts, and total loss protection.

Reputation and Warranty Reviews

Buying an extended warranty for your car involves many steps. One is selecting a provider you can trust to be upfront about what you’re getting. You also want a company with positive reviews.

Endurance has a history of favorable customer reviews. On the Better Business Bureau (BBB) website, Endurance maintains a 3.64 out of 5-star rating, over 3,700 reviews, and an A- BBB rating (as of June 2024). Cornerstone United maintains 1 out of 5 stars from the BBB.

On Consumer Affairs, you’ll see comments, like from Samantha in Acworth, GA, sharing: “I had tried a couple of other companies and Endurance was the third one I talked to and I liked their plan. Their customer service was great.”

Another customer, Kenny from Jacksonville, FL, remarked: “Very good warranty company. Very easy to use. Pays straight to mechanic after service is complete. I highly recommend this warranty company.” There are no reviews on Consumer Affairs for Cornerstone United.

Google provides additional insights into both companies. Endurance has over 12,000 consumer ratings, with an average score of 4.1 out of 5 (as of June 2024). A dive into individual feedback uncovers positive comments such as, “They approved a new motor, new turbo, ignition, radiator, and all the extras….A Very Happy Camper,” from Jay W. And Tak W. shared:  “The Endurance warranty representative went above and beyond in guiding me through the process of starting a warranty claim.”

Google reviews are less favorable for Cornerstone United, which has an average rating of 3.7 out of 290 reviews. Numerous Cornerstone customers have left positive feedback, with comments like “No complaints here” and “They covered the very expensive cost of repair.”

However, one review points to a potential flaw in Cornerstone’s business model: relying on dealers as part of the sales process. One Cornerstone customer shared that the contract on file with the company does not match the one signed at the dealership, affecting a claim for an engine replacement.

It circles back to how each company discloses information. Endurance is upfront, offering sample contracts that can be viewed online before getting a quote or talking to anyone. All Cornerstone offers are marketing brochures that don’t provide specific extended warranty coverage details. To view exactly what’s covered by a Cornerstone extended warranty, you’ll have to contact a participating dealer and request a copy.

Consumer Resources and Pricing

Knowing what you’re buying when it comes to extended warranties is essential for a successful experience. This belief goes hand-in-hand with Endurance’s efforts to educate consumers through an extensive learning center and detailed FAQs. The Endurance blog features hundreds of articles, many written by ASE Certified mechanics, that cover extended warranties, car maintenance, DIY tips, and more. At the same time, the Endurance website features an extensive FAQ section with dozens of answers. While Cornerstone does have an FAQ area on its website, there’s no blog with consumer-friendly information.

The most important aspect of transparency involves pricing. Endurance’s nothing-to-hide philosophy includes stating upfront that coverage begins at low monthly rates. In addition, Endurance offers instant online pricing. Just enter a few details about your car, and you’ll quickly learn how much an extended auto warranty costs. An Endurance advisor can walk you through additional coverage options and answer any questions.

Cornerstone isn’t as direct — you’ll only get a price from a car dealer, who isn’t likely to provide this information online or over the phone. Further, buying an extended warranty through a dealer means paying a marked-up price. The dealer buys the service contract from Cornerstone and adds a profit to determine what you’ll pay.

Buying from Endurance cuts out the middleman because we are a direct provider of our vehicle service contracts, ensuring you don’t leave money on the table.

	Endurance Warranty	Cornerstone United
Sample Contracts	Yes	No
Blog	Yes	No
FAQs	70+	8
Online Pricing	Yes	No

Being upfront is at the heart of how Endurance conducts business. Consumers have ready access to all the information they need to decide about an extended warranty. There are no hidden details.

Drive Forward With Endurance for the Best Coverage

Learn all the benefits an extended auto warranty can offer your used or new vehicle – and take advantage of our 30-day money-back guarantee! Explore our online store for instant price and plan details, or request a FREE quote. One-on-one help is available by calling the Endurance team at (800) 253-8203. Our plan advisors are ready to answer your questions and review coverage options customized to your needs.