Text reads: The Mysteries of Life with Tim and Moby.

Tim and Moby are standing in front of a gas station in the middle of the desert. Tim is looking under the hood of their car while Moby is sipping out of a cup through a straw. A vulture lands on the open hood of the car, scaring Tim.

TIM: Aaaah!

The vulture drops a piece of paper in front of Tim. Tim reads from the typed letter.

TIM: Dear Tim and Moby, How does a car work? Sincerely, Steven. Thanks for writing in, Steven! Most cars are powered by an internal combustion engine. That’s a machine that converts an explosion’s energy into motion. The key to the internal combustion engine is something called the cylinder.

A simple outline of a car is shown. The engine is connected to the gas tank. An animation zooms in on it to show the structure of the cylinder.

TIM: Burning gasoline creates a tiny explosion inside the cylinders.

An animation shows the tiny explosion at the top of the cylinder.

TIM: This explosion’s pressure forces another part called the piston down, which transfers the energy to the wheels.

An animation shows what Tim describes.

MOBY: Beep?

TIM: When you press down on the gas pedal, you’re letting more air into the cylinders.

An animation shows a foot pressing down on the gas pedal and air entering the cylinder.

TIM: The oxygen in the air creates a bigger explosion — which provides more power, and makes the car go faster!

The scene changes to show only the cylinder and a series of explosions and piston movements.

TIM: An engine has a lot of moving parts; that’s why it needs motor oil. The oil reduces friction in the parts that rub up against one another.

Moby looks at a bottle of motor oil that Tim is holding, extends his arm, snakes it around Tim from behind, and grabs the bottle of motor oil.

TIM: It also cleans the engine and prevents all those parts from overheating.

Moby takes out a straw, sticks it in the bottle of motor oil, and starts sipping on it.

MOBY: Beep!

Moby belches after he finishes drinking the bottle of motor oil.

TIM: Ah, okay . . . There’s plenty of other stuff going on inside the car, too. The transmission is a complicated set of gears.

A simple outline of a car is shown. The engine is connected to the gas tank and a call-out bubble shows an enlarged view of the transmission.

TIM: Just like on a bicycle, changing gears allows your engine to operate smoothly and safely at both low and high speeds.

An animation shows the inner structure of the transmission.

TIM: The battery is like a really big version of the small batteries you have in your house! It powers the car’s electrical system — everything from the clock on your dashboard to the headlights.

An image shows the battery in the engine compartment of the car.

MOBY: Beep!

TIM: The brakes are discs or drums that sit near your car’s wheels.

A split screen shows disc brakes and drum brakes.

TIM: They use friction to help you slow down, or stop! And the suspension is the system of springs and shock absorbers that connects the body of the car to the wheels. A good suspension will allow you to drive along a bumpy road without bouncing up and down out of your seat!

An image shows a wheel with a suspension mechanism attached to it. A split screen animation shows two robots in cars. The car on left is barely moving up and down while the car on the right is bouncing up and down wildly.

TIM: And it also prevents a total body collapse.

The animation shows the car in the right half of the screen drop to the ground and stop moving.

MOBY: Beep!

Moby and Tim look at each other. Moby's face is extra orange and a spray of hissing steam comes out of his neck.

TIM: Oh no — have you overheated, buddy?

Moby nods.

TIM: Here you go. This should set you right.

Tim hands Moby a bottle of water with a straw. Moby drinks the water, returns to his normal shade of orange, and smiles. He then sends a spray of water out of his finger and into Tim's face.

TIM: Okay, I’ve had it, are you gonna mess around, or are you gonna help me fix this car?

MOBY: Beep!

Moby is now lying on a dolly, dressed as a mechanic. He slides underneath the engine block with a wrench, and gets to work.

TIM: Okay then.

Tim in stands in front of the car and looks down at Moby.

TIM: Anyway, as you probably know, cars make pollution. When a combustion engine burns gasoline, it produces waste gases, like carbon dioxide and sulfur dioxide. They leave the car through the tailpipe and enter into the air.

An animation shows clouds of smoke coming out of the tail pipe of a car.

TIM: That’s why most cars have a device called a catalytic converter, which changes harmful exhaust gases into slightly less harmful ones.

While the animation of exhaust fumes leaving the tail pipe continues, a callout bubble shows an image of a catalytic converter. It is a long, metal cylinder with bolt-mounts at each end.

MOBY: Beep?

TIM: Nah, they didn’t have cars back then. The first automobiles were built in the 1880s. And they didn’t look anything like the cars of today!

An animation shows two men wearing long overcoats and top hats riding a carriage with a pair of pipes attached to the front. The rear wheels of the carriage are much bigger than the front wheels.

TIM: They weren’t too popular, either — they took a lot of time to make, and cost a ton of money.

An animation shows a single man riding in a different carriage. All four wheels are the same size, the carriage has a soft top, and the man is holding onto a wooden handle.

TIM: They were basically expensive toys for rich people. Then, in 1913, American automaker Henry Ford started building cars using a moving assembly line.

An image shows a gray-haired Henry Ford dressed in a suit and tie, standing in a field. Behind him is a black car with a windshield, a soft top, and a steering wheel.

TIM: This allowed cars to be built much more quickly, and cheaply. Pretty soon, all sorts of people were able to buy cars!

An animation shows a modern city skyline in the background, with cars driving on a paved road in the foreground.

TIM: There’ve been a lot of new developments since then. Among the latest are hybrid cars, which run on a combination of gasoline and electricity!

An image shows a modern hybrid car.

TIM: If you’d like to find out more about those, check out our Hybrid Cars movie.

MOBY: Beep!

Moby, still dressed as a mechanic, is resting against the hood of the car. The front of the car sparkles.

TIM: Wow, Moby, great job! For once, I have to thank you for sticking to an important task without goofing around at all.

Moby stands up straight and sends a spray of water out of his finger, hitting Tim on the head.

TIM: Or not.