(iSeeCars) – When purchasing a new vehicle, buyers receive two primary warranties: the bumper-to-bumper warranty and the powertrain warranty. Combined, these warranties ensure thorough protection against premature failures in your new or nearly new automobile.

The powertrain warranty specifically covers the costliest parts of your vehicle, although many buyers might find its inclusions and exclusions confusing. We provide a detailed explanation of what is typically included in a powertrain warranty.

What is the Powertrain?

The powertrain of a vehicle consists of essential parts responsible for generating power and transmitting it to the wheels. These components include the engine, transmission, differential, and axle shafts. Depending on whether the vehicle is configured as front-wheel, rear-wheel, or all-wheel drive, it may also include the transaxle, driveshaft, and transfer case. Essentially, any component involved in producing or transferring engine power is considered part of the powertrain.

As you might imagine, these parts are complex pieces of engineering – there’s nothing simple about an engine or transmission. When there’s a major failure with one of these parts, the cost can be high due to the labor hours necessary for repair as well as the cost of obtaining replacement parts. This is becoming doubly true as cars incorporate more and more technology under the hood. 

All vehicles also have something called a drivetrain, a term that can be easily confused with the powertrain. The drivetrain, however, focuses on the driven wheels. All-wheel drive (AWD), four-wheel drive (4WD), front-wheel drive (FWD), and rear-wheel drive (RWD) are the four types of drivetrains. The components of these drive systems are covered by the powertrain warranty. (For more on drivetrains, refer to our guides: 4WD vs. AWD and RWD vs. FWD.) 

What is Covered by a Powertrain Warranty?

The powertrain warranty is a type of limited warranty that covers the cost of any repairs or replacement of any of a vehicle’s powertrain component. 

Exactly what is protected differs in detail from warranty to warranty. Typically, covered parts include seals and gaskets, internal parts like the crankshaft, pistons, valves, fuel injectors, and timing chain, the cylinder block and oil pan, transmission gears and synchronizers, and all the hardware that composes the differential and axle systems.

It’s important to note that coverage of all these components can be voided if the vehicle has been altered from factory specifications, if it has been used irregularly, or was otherwise intentionally abused. What this means is that you shouldn’t expect a powertrain warranty to cover the damage arising from off-roading your Mitsubishi Mirage.

Getting in an accident also voids the warranty. Any powertrain repairs needed as the result of a collision will be covered by your insurance, not the warranty. 

Also, be sure to take your car to authorized service providers and dealerships when it’s time for a warranty claim; the work of a local independent mechanic will not be covered by the terms of the factory warranty. 

What is Not Covered by a Powertrain Warranty?

With every warranty, there’s a long list of exclusions as to what’s not covered; sometimes this list seems longer than the list of covered parts. As we mentioned, the particulars of what is and isn’t included differs with every manufacturer, but a common theme is that all electronics, engine control module sensors, belts, hoses, emissions, and cooling systems are not covered. Wheel bearings, catalytic converters, oil pumps, and water pumps are other parts that are potentially not covered.

A good rule of thumb is that anything considered to be a wear item is not covered by a powertrain warranty. For instance, if your clutch goes on your manual-transmission car, don’t expect the dealership to cover the replacement cost. Even if it lasted just 20,000 miles, the service department will simply call it a wear and tear item and hand you the bill. The same goes for other items such as the timing belt or CV joints, which are considered wear items and will not be covered by a warranty.

Common maintenance items like oil changes, tire rotations, and brake pads will also not be covered. The warranty is designed to protect car owners from unexpected repairs, not pay for routine maintenance.

If you don’t want to be surprised at your local mechanic about what is and isn’t covered by your service contract, you’ll need to read the fine print regarding your warranty coverage. It doesn’t matter whether you’re buying a new car with factory coverage or some third-party warranty – the contract will clearly spell out the terms of the warranty.

How Long Does a Powertrain Warranty Last?

The length of a powertrain warranty differs with every manufacturer, but coverage terms are usually written like this: five years or 60,000 miles, whichever comes first. The longest-lasting warranty belongs to Hyundai, Kia, Genesis, and Mitsubishi; which include powertrain coverage that lasts for ten years or 100,000 miles. The Korean brands have been providing decade-long powertrain coverage since the late 1990s; twenty years later their warranty remains the most long-lasting in the industry. Here is a list of automakers and the length of their powertrain warranties:

How Does a Powertrain Warranty Differ from a Bumper-to-Bumper Warranty?

Together, these two auto warranties are known as the manufacturer’s warranty. The powertrain warranty covers the most expensive, crucial mechanical components of your vehicle. As previously noted: if it has to do with the direct creation or flow of power, it’s part of your powertrain and would fall under the terms of a powertrain warranty. 

The bumper-to-bumper warranty, on the other hand, is a comprehensive warranty that covers any systems and components that don’t fall under the powertrain warranty. Suspension and brake components that aren’t considered wear and tear items would fall under the bumper-to-bumper warranty, as would the power steering system, air conditioning, infotainment system, and lighting systems. 

The bumper-to-bumper is intended to protect against shoddy workmanship, defective materials, or any other premature failures that aren’t due to neglect, abuse, or wear. Typical bumper-to-bumper warranties only last about three years or 36,000 miles, which is less than the typical five years or 60,000 miles of coverage provided by a powertrain warranty.

Should I Buy an Aftermarket Extended Powertrain Warranty?

Plenty of companies offer extended warranty coverage to concerned buyers looking for the peace of mind provided by a warranty. These third-party warranties typically cost $1,000 to $3,000, depending on the extent of coverage as well as the age and mileage of the used vehicle to be covered. 

Considering that the cost of powertrain repairs can be in the thousands, an extended third-party warranty can look like a tempting proposition. But it only looks that way: in truth, most buyers of these extended powertrain warranties never actually use them. If they do, the cost of repairs often turn out to be less than the cost of the warranty. 

A better financial decision is to save what a third-party warranty would cost you in an account that’s earmarked for emergency car repairs. If you need to tap into it because of an unforeseen trip to your mechanic, the money is there; if you don’t need it, you have extra savings toward your next vehicle purchase.

For more information on aftermarket warranties, read our article on extended car warranties.

The Bottom Line

The powertrain is the heart of an automobile. If any component in this integrated series of systems fails, your car becomes undrivable. A properly working powertrain is vital to having a reliable, dependable vehicle. 

The powertrain warranty is a welcome safety net in the event your car suffers a major premature failure of any major mechanical system that could require expensive repairs. A powertrain warranty protects the consumer and also allows them to feel better about their purchase. Automakers benefit as much as the car buyer: Hyundai and Kia, for instance, saw their own sales increase markedly after the introduction of their ten-year warranty. 

Whatever car you’re buying, read the fine print about any powertrain warranty that may be included or offered with the sale. Know the duration of coverage, what is and isn’t covered, and what any deductibles might cost if you do need to use the warranty. Being informed is the most effective way to avoid any surprises during the warranty period.

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This article, What is a Powertrain Warranty and What Does it Cover?, originally appeared on iSeeCars.com.