Under the Hood

The Under the Hood Channel explores the systems that make your car function correctly. Learn about car parts and systems and how to do routine maintenance.

Topics to Explore

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How Adaptive Headlights Work

Car accidents occur often at night, and part of the reason might be that your headlights just aren't good enough. Adaptive headlights alleviate the visibility problems you experience every time you take the car out after dark.

How Clutches Work

You probably know that any car with a manual transmission has a clutch -- it connects and disconnects the engine and transmission. But did you know that automatics have clutches, too?

How the Tweel Airless Tire Works

For more than 100 years, vehicles have used pneumatic, or air-filled, tires. Michelin's alternative is the Tweel Airless Tire. Could it replace traditional tires?

How Ford Sync Works

Ford's Sync system pioneered many of the mobile connectivity features that are now commonplace in new cars. However, you don't necessarily need to be a social media fanatic to enjoy all the benefits Sync has to offer.

How Radar Detectors Work

If you have a lead foot you may have invested in a radar detector. Find out how these devices pick up police radar and lidar and learn what a jamming signal does.

How the GMC PAD Works

The GMC PAD is basically a futuristic motor home -- part apartment, part vehicle, and part telecommunications center.

How Dual-clutch Transmissions Work

Most people know that cars come with two basic transmission types: manuals and automatics. But there's also something in between that offers the best of both worlds -- the dual-clutch transmission. Check it out.

How OnStar Works

Its critics call the popular telematics service "Big Brother" and claim that it can lead to an invasion of privacy. Explore the technology behind OnStar and learn about the controversy.

How Superchargers Work

Since the invention of the internal combustion engine, automotive engineers, speed junkies and race car designers have been searching for ways to boost its power. And they did, of course -- creating superchargers that make an engine more efficient by forcing air into the combustion chamber.

Traction Control Explained

Traction control helps limit tire slip in acceleration on slippery surfaces. Many of today's vehicles employ electronic controls to limit power delivery for the driver, eliminating wheel slip and helping the driver accelerate under control.

How Quasiturbine Engines Work

The quasiturbine engine takes the Wankel concept and improves on it: Instead of three combustion chambers it has four and the setup of a quasiturbine allows for continual combustion. Learn all about the quasiturbine.

How Car Suspensions Work

In this article, we'll explore how car suspensions work, how they've evolved over the years and where the design of suspensions is headed in the future.

How CVTs Work

In a regular transmission the gears are literal gears -- interlocking toothed wheels. Continuously variable transmissions, on the other hand, don't have interlocking gears. The most common type operates on a pulley system. Learn all about the smooth-operating ultra-efficient CVT.

How Self-inflating Tires Work

Self-inflating tires perform two crucial functions: They automatically maintain ideal tire pressure and they allow you to alter psi on the fly to adjust to changing terrain. Learn about self-inflating tires.

Inside Engines

Our engine roundup page page takes you straight to the power. See what's under the hood from the HEMI to the Wankel.

How HEMI Engines Work

Even if you don't know much about cars, the word "HEMI" might still mean something to you. It's become a synonym for big, powerful engines.

How Sequential Gearboxes Work

Combine the ease of an automatic with the driver control of a manual and what you've got is a sequential manual transmission. A simple forward push advances the gear. Learn all about the sequential gearbox.

How E-ZPass Works

If you're a regular on toll roads, you probably either know about E-Zpass or you already have one. Learn all about this ingenious and convenient technology and how it automatically lets you pay your way.

How Car Alarms Work

They beep wail and some yell at you (yes yell!). Auto alarms are complex these days with sensors that set off the siren before a potential thief even touches the car. Learn all about car alarms.

What does 2.4 liter mean in the context of an engine?

This may sound silly but on the back of my car there is a little sign that says "2.4 liter" and every morning I see that and wonder "What does that mean?" So what does it mean?

How Car Steering Works

When it comes to crucial automotive systems, steering is right up there with the engine and the brakes. The inner workings of this important component are pretty cool. Find out all about car steering systems.

How Turn Signals Work

To most drivers turn signals seem pretty simple: There’s a lever that makes your signal lights flash. But there’s actually some cool technology at work. Find out how this under-used device operates.

Why is there a bulge in the exhaust pipe of my dirt bike?

I have a dirt bike and the exhaust pipe has this big bulge in it near the engine. What is the bulge for?

How Stirling Engines Work

The Stirling engine is a heat engine that is vastly different from the internal-combustion engine in your car. It has the potential to be more efficient than most types of engines, but it hasn't made it into mass production yet. Find out why.

How Convertibles Work

Warmer weather means convertible season -- ever wonder what's behind that thrilling ride? How is it that a car can go from everyday coupe to sporty convertible at the push of a button? Find out.