A properly functioning powertrain is necessary to move down the road and power through difficult road conditions. The engine generates horsepower, which runs through the transmission and driveshafts before turning the wheels and propelling the vehicle forward or backward.

Unlike a faulty light switch or a window that won't open, the powertrain is at the very heart of an automobile's ability to perform. While you can perhaps live with minor mechanical quibbles here and there, if something goes wrong with the powertrain, your vehicle is essentially shipwrecked.

The specific parts that make up an internal combustion engine car's powertrain include:

• Engine: The engine generates the power needed to move the car by burning gasoline (or, for some vehicles, diesel) as fuel. The fuel ignites within cylinders, causing pistons to move up and down and rotate a crankshaft. This crankshaft rotates the gears in the gearbox.
• Transmission: The transmission controls the engine power delivered to the wheels by letting you shift between gears in the gearbox. For automatic transmissions, the shifting happens without your input.
• Driveshaft: The driveshaft transfers the power from the transmission to the axles.
• Axles: The axles transfer the power from the driveshaft to the wheels.
• Differentials: Differentials are small devices that let the wheels turn at different speeds on the same axle. For example, when making a turn, the outside wheel rotates faster than the inside wheel.
• Supercharger or turbocharger: Both of these are devices in the engine that can help add power to a vehicle by manipulating the amount of air supplied to the engine.
• Transfer case: This transfers power from the transmission to both axles in all-wheel-drive and four-wheel-drive vehicles. Front-wheel-drive and rear-wheel-drive vehicles don’t have a transfer case.

Buying a used vehicle is a wise financial decision, potentially saving you thousands of dollars. But how can you know you're buying one in excellent mechanical condition?

Shift's certified mechanics perform extensive 150-point inspections on every car and have complete vehicle history reports, so you know when you buy with Shift, your used car feels as good as new. And Shift offers best-in-industry service contracts, ensuring your vehicle runs strong year after year.

Powertrains vs. drivetrains: What’s the difference?

Powertrains and drivetrains are similar. In fact, the drivetrain is part of the powertrain.

The drivetrain consists of all components that deliver power to the wheels, including the transmission, differentials, and all the parts in between. Some, however, don’t consider the transmission to be part of the drivetrain.

Regardless, the internal combustion engine, other engine components, and all the drivetrain components make up the powertrain. That means turbochargers and superchargers are part of the powertrain but are not part of the drivetrain.

Electric vehicle powertrains

Electric vehicle (EV) powertrains are different since, well, they use electric power instead of gas. Though they tend to have fewer moving parts than gas-powered vehicles, that doesn’t necessarily translate to more reliability.

Still, there are several EV powertrain components you won’t find in a car or truck with an internal combustion engine. These include the following:

• Battery pack: This contains the energy the EV needs to run. It provides the DC output.

• DC-AC converter: This converts the DC current to AC current. Without getting technical, power from the grid is always AC. EVs run on AC power. EV batteries can only store power as DC.

• Electric motor: This turns electrical energy into mechanical energy, which the transmission delivers to the wheels.

• On-board charger: This converts AC power from the grid to DC for battery storage. It also controls the level of current flowing into the battery.

• Battery management system: This system monitors the battery to ensure it’s working properly and takes certain steps if a malfunction occurs.

• DC-DC converter: This moves the DC power to various systems in the car that need different levels of electricity to function, like the wipers and infotainment system.

• Thermal management system: This system keeps the temperature of the powertrain’s components within the necessary range.

• Body control module: This monitors and controls the functions of the car’s electronic accessories.

Hybrid powertrains

Hybrid powertrains can contain elements from ICE and EV powertrains. The components a hybrid vehicle includes depend on what kind of hybrid it is.

Two kinds of powertrains can be in a hybrid vehicle: parallel or series powertrains. Without diving into all the scientific details, parallel hybrid vehicles connect their internal combustion engines and electric motors to the transmission independently. Meanwhile, series hybrids connect the engine to the electric motor using the engine’s energy to power the motor.

The price of repairing a powertrain depends primarily on what needs to be fixed. The more parts that need repairs, the more you’ll have to spend on repairs.

Also, some parts simply cost more than others.

A few other factors can influence how much you’ll pay to get your powertrain fixed. These include the following:

• The car’s make/model: Luxury cars and other expensive vehicles typically cost more to fix because their parts are more expensive. They might also require specialized knowledge, depending on the vehicle.

• The repair company: Companies charge different amounts for the same repairs, usually due to labor costs.

A powertrain warranty protects the complex system of parts that make your vehicle go.

Powertrain warranties focus on specific areas essential to a vehicle's driving performance. As mentioned, these are the engine, transmission, driveshafts, transfer case, axles, differentials, and turbochargers or superchargers.

What if a cylinder misfires in your engine, leading to a host of other problems and immobilizing your car? That's where the powertrain warranty kicks in. Or you shift your transfer case to switch to four-wheel drive, and nothing happens? A powertrain warranty covers the repairs to get it going again.

Bumper-to-bumper warranties usually receive the most attention because they cover a lot more and tell you more about an automaker’s confidence in their vehicle’s reliability. However, powertrain warranties last longer and ensure the most critical parts of your vehicle work properly.

For a powertrain warranty to remain in effect, the owner has their own set of responsibilities. Performing manufacturer-recommended maintenance like oil changes, filter changes, and installing new spark plugs not only keeps your vehicle running its best — minimizing the chance that you’ll need to make a costly repair — but also ensures you retain powertrain warranty coverage.

Additionally, powertrain warranties cover vehicles driven under normal conditions. So if you decide to take your sports car to the race track for some fast laps, a typical powertrain warranty won't cover this additional strain on the engine and transmission. Or, if you take your pickup truck or SUV for some heavy off-roading, most powertrain warranties won't cover a broken transmission.

As reassuring as powertrain warranties are, they don't cover everything. Some elements of the powertrain may not be included in a powertrain warranty.

Powertrain warranty exclusions apply to different areas of the drivetrain, like engine wiring and fuel system, transmission clutches, transfer case cooling lines and radiator, and parts of the drive system like wheel bearings and locking hubs.

Additionally, a powertrain warranty doesn't apply if you're in a collision and your vehicle suffers damage as a result. Or, if you decide to perform aftermarket modifications to gain added horsepower, causing engine damage in the process, the warranty won't pay for repairs. While not all modifications will void your warranty, this is a gray area — so it might be best to err on the side of caution.

Other situations that exclude powertrain warranty protection are damage caused by poor quality fuel, environmental causes, or improper maintenance.

When you buy a used car, it's comforting to know you have extra reassurance for the years and miles ahead. Shift's vehicle protection plans cover your vehicle from the sheet metal to the tires, offering comprehensive protection no matter what you encounter.

Flat tire on a back road? With Shift's vehicle protection programs, you receive free assistance to get moving again. Other benefits include rental car reimbursement, free towing, and jump starts if you're stranded.

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Typically, a manufacturer's powertrain warranty lasts longer than a bumper-to-bumper warranty. Bumper-to-bumper warranties usually last around three years or 36,000 miles, while powertrain warranties remain in effect for about five years or 60,000 miles.

However, a range of powertrain coverage terms exists among manufacturers. While the powertrain warranty on a Jaguar covers five years or 60,000 miles, Kia and Hyundai offer protection for 10 years or 100,000 miles. Lincoln and Cadillac provide six years or 70,000 miles of powertrain coverage.

Once the manufacturer's powertrain warranty expires, you have the option of purchasing an extended warranty from a third-party company.

As cars rack up miles over the years, wear-and-tear occurs, and repairs may be necessary. As time goes by, powertrain longevity is especially significant to a used vehicle, which provides critical propulsion and driving performance.

If you'd like to keep your car for a long time and want to drive without worrying about engine trouble, an extended powertrain warranty makes sense.

Depending on your budget, different coverage levels are available, and you receive peace of mind for the miles ahead.

How much do extended powertrain warranties cost?

In general, extended powertrain warranties cost around $3,000 and last between three to six years.

However, the price will depend on several factors, including the following:

• The warranty company: Companies may offer different prices for the same coverage, so shopping around is important.
• The deductible: This refers to how much you are responsible for paying before the warranty covers the rest. A higher deductible will reduce your monthly payments and vice versa.
• The term length: This represents how many years the warranty will last. The longer the term, the pricier the coverage.
• The vehicle type: Luxury vehicles cost more to repair in terms of parts and labor, so covering these will cost more. Additionally, older vehicles tend to break down more often than newer ones, increasing the warranty prices for these vehicles.

Searching for a reliable used car can be a hassle. Not only do you want a great price, but you don't want the stress of negotiation that spoils the experience. Whether you need an electric car or an SUV, Shift's no-pressure environment makes buying a used car easy. Shift offers fair, no-haggle prices driven by powerful machine-learning algorithms and tons of data.

Shift works with several third-party providers to offer you different warranty plans at affordable monthly rates, too.

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A powertrain warranty provides coverage for areas essential to your vehicle's driving performance, like the engine, transmission, and driveline.

In general, powertrain warranties cover lengthier terms than bumper-to-bumper warranties, but they don't protect other parts like the electrical system or suspension.

Remember, as your vehicle gets older, purchasing an extended powertrain warranty makes sense in order to ensure your engine remains protected as the miles add up.