The diagrams are clickable
Every section has one big overview diagram with numbered markers. Click a marker and the page jumps straight to the card that explains that part.
What this project is
CarCurious is an illustrated reference for anyone who has ever looked under the hood and thought: what is all of this? Every system — engine, transmission, brakes, suspension, electrics, safety — is taken apart into its components, drawn as a diagram and explained in plain language.
It was built for learning and plain curiosity: to answer the questions a driver actually has, like why cold brakes squeal, what the gearbox is really doing between gears, or why an electric car still needs a small 12-volt battery.
No technical background is needed. There is nothing to install, nothing to sign up for and no order to follow — open whichever section you are curious about.
How to use the site
Three things worth knowing before you start
Watch what moves
Parts that really move in a car are animated — pistons, gears, brake pads, shafts. Housings and frames are drawn still, so you can see at a glance what is moving and what is holding it.
Your language, your theme
The whole site is available in four languages and follows your light or dark preference. Both switches are in the header, and your choice is remembered.
A few curious facts
Small things that make the rest of the site easier to picture
About 30,000 parts
Counting every screw and clip, a modern car is assembled from roughly 30,000 individual parts — and only a few hundred of them are ones a driver ever sees or touches.
25 explosions a second
At 3,000 rpm each cylinder of a four-stroke engine fires 25 times per second. In a four-cylinder engine that is a hundred controlled explosions every second, each one timed to within a fraction of a degree.
Brakes make heat, not nothing
Braking does not destroy energy, it converts it: on a long descent brake discs can pass 500 °C. An electric car sends part of that energy back into its battery instead of throwing it away as heat.
Four postcards of grip
All four tires together touch the road over an area about the size of four postcards. Every bit of accelerating, braking and steering has to pass through those few patches of rubber.
9,000 litres of air per litre of fuel
Petrol only burns in the right proportion with air — about 14.7 kg of air per kilogram of fuel, which works out at roughly 9,000 litres of air for every litre in the tank. That is why an engine needs an intake as much as a fuel line.
20,000 volts to cross a millimetre
The ignition coil turns the car's 12 volts into 20,000–30,000 volts just so a spark can jump the tiny gap in a spark plug — a gap smaller than a millimetre, refilled with fresh mixture every cycle.
Free, and staying free
CarCurious costs nothing to use. There are no ads, no trackers, no accounts and no locked sections — every diagram and every explanation is open to everyone, in all four languages.
If something here finally made a part of your car make sense, you are welcome to say thanks with a small tip — but sending the site to someone else who is curious is just as good.
Say thanksA note on accuracy
Everything here is deliberately simplified for learning. The diagrams are schematic rather than engineering drawings, and details differ between makes, models and model years. Use the site to understand how things work — not as a repair manual, and not in place of your car's own owner handbook.
Get in touch
Found a mistake, or have a question or an idea for the catalog? Write to hello@carcurious.org.