What is a Powertrain for Cars and Warranties?
Let’s explore these automotive terms more thoroughly so you can more confidently determine the value and adequacy of a new vehicle’s powertrain warranty.
What is a powertrain?
Powertrain vs. drivetrain
A car’s drivetrain is simply the parts that receive power and turn it into motion. From the transmission to the wheels takes the engine or electric motor’s energy and transforms it into kilometers passing under the tires.
Drivetrains differ mostly by the car’s driven wheels. Front-wheel drive (FWD), rear-wheel drive (RWD), all-wheel drive (AWD), and four-wheel drive (4x4) use slightly different methods and layouts to take power from the driveshaft and transmission and bring it to the axles and wheels.
ICE powertrain
The powertrain of a standard internal combustion engine (ICE) car includes the:
- Engine
- Transmission
- Driveshaft
- Differential
- Axles
The ICE engine turns fuel and air into thousands of little explosions pushing against pistons that turn a crankshaft within the engine’s core. The engine includes its fuel system, from the gas tank to the injectors. It also includes computer management, charging, cooling, intake, emissions, and exhaust systems.
With a few parts in between to manage power delivery, the engine’s crankshaft turns the gears with the transmission. Transmissions are incredibly complex machines, whether automatic, manual, or continuously variable (CVT) — found in most hybrids. The transmission connects to the driveshaft, like in traditional rear-wheel drive cars, or to constant velocity (CV) joints in front-wheel drive applications.
A driveshaft is a long connector extending from roughly the middle of the car where the transmission ends to the rear axle, between the rear wheels. A CV joint is much shorter because the engine and transmission sit right next to the front wheels. CV joints handle power delivery and need to be able to steer and turn, so they have a special joint that bends and rotates simultaneously.
Differentials sit between the transmission and the axle/wheel assemblies. Differentials are used to take a single power source — like a driveshaft — and allow it to be sent to two wheels in varying proportions. Why? When driving straight, both the left and right wheels spin at the same speed. But when turning, the inside wheel spins slower than the outside wheel (which has to travel a longer arc at the same time). The differential allows this difference in wheel speed to avoid a wheel dragging or pulling (which you might hear as tire squeal or feel as wheel hop).
Finally, axles connect the wheel, hub, brake, and tire assemblies with the rest of the powertrain to actually put the energy to the road as forward momentum. Axles also vary in size, placement, and design based on front, rear, all, and four-wheel drive layouts, but the essential concept remains consistent. Axles contain a central rotating shaft that runs perpendicular to the driveshaft and direction of motion to bring torque from the differential to the road and spin those wheels.
But what if you’re buying an electrified vehicle?
Electric vehicle (EV) powertrain
In an electric vehicle, the powertrain includes the:
- Charger
- Battery
- Power converters
- Electric motor(s)
- Transmission
- Axles
- Regenerative brakes
Power converters in an EV come in two types. DC-AC converters turn the battery’s energy into power for the electric motors, while DC-DC converters transform the battery’s high voltage into lower voltage for electric accessories like lights and wipers. Computer management systems dole out the right amount of power each motor and accessory needs based on driver inputs and powertrain sensors.
The EV’s motor sends power to a (typically) single-speed transmission. Since electric motors can spin at incredibly high revolutions per minute (RPM) and provide near-instant torque, they don’t need the same complex gearing as ICEs.
The transmission transmits power to the axles, which spin the wheels and make motion happen. On an EV, brakes are especially important to the powertrain — but how do brakes make a car go?
Regenerative braking is used in EVs to capture the kinetic energy of the vehicle coasting and store it as electricity in the battery instead of heat and friction on the brake pads and rotors. This process reverses the flow of electricity, letting the wheels spin the axles, transmission, and electric motor backward. That rotational energy creates electricity, which tops up the battery for later use.
Hybrid powertrain
Combining ICE and EV elements, hybrids offer an innovative combination of powertrain technology in a few styles:
- Traditional gas-electric hybrids with an electric motor sandwiched between the ICE engine and transmission, which allows the engine to turn off (saving fuel) and let electricity do some pushing
- Mild hybrids with small electric motors and capacitors that provide only short electric boosts but with minimal added weight
- Plug-in hybrid electric vehicle (PHEV) powertrain layouts add an external charger and slightly larger battery than a hybrid, allowing for longer overall and battery-only range plus less reliance on gas stations
A hybrid powertrain includes:
- Engine
- Transmission
- Electric motor(s)
- Battery or capacitor
- Axles
- Regenerative brakes
- Power converters
- Differentials
As you can see, they have most components of both an EV and an ICE car. Even though the engine and battery are usually smaller than full gas or electric models, hybrid powertrains are still carrying around multiple power sources. While there are a few variations of hybrid layouts, most are parallel hybrids but some are also series hybrids, which use a traction motor in place or in addition to a transmission.
However, their efficiency and flexibility — not to mention range — make them a leading choice for drivers wanting eco-friendly and budget-friendly vehicles that still have the power to excite.
What is a powertrain warranty for a car?
In an EV or hybrid, the powertrain warranty may cover the electric components. Or, a separate warranty might also exist to meet the unique needs of electric motors, batteries, chargers, and other systems.
Having a comprehensive powertrain warranty is important for reliability and peace of mind. A powertrain warranty is a manufacturer’s way of guaranteeing their work — they expect the car’s powertrain to work flawlessly (if properly maintained) for the given number of years and kilometers under normal use. If it doesn’t, they stand by their machines and offer to repair or replace the worn-out parts.
Without a powertrain warranty, drivers could be liable for many thousands of dollars when critical systems break down.
Mitsubishi pursues not just relentless innovation in powertrain technology, but also one of the most competitive powertrain warranties in the industry. The 10-year, 160,000-kilometer powertrain warranty on new Mitsubishis covers the critical powertrain components, so you get quality, reliability, and durability you can trust.
Learn more about Mitsubishi’s comprehensive powertrain warranty to enhance your driving experience with reliability and assurance.