It tells the capacity of the engine the car has.
For starters : 1 Litre = 1000 cc (cc means Cubic Centimeters or cm^3)
So a 1.2L car is:
1.2×1000= 1200 cc
Likewise a 1.4 L car has a 1400cc engine;
and so on.
Also note that if a 1.2L car has a 4 cylinder engine, it means each cylinder’s capacity is 1200÷4 = 300 cc
Volume of a cylinder is :
(π(D^2)h)÷4
where D is the diameter of the cylinder called Bore Diameter and h is the height of the cylinder called Stroke Length.
Thus when you calculate the volume of each cylinder of a 4 cylinder 1200cc car, using the above formula by measuring the bore and stroke yourself you’ll end up getting 300cc or some no. very close to 300cc since π isn’t an absolute no.
Now for the technical part :
How does that matter?
Well the performance of an engine (Horsepower, Torque, Acceleration, etc.) depends upon how much fuel it can burn when the Piston inside the cylinder reciprocates once; i.e. when it moves from the topmost point of the cylinder called Top dead center (T. D. C.) to the lowermost point of the cylinder called the Bottom dead center (B.D.C.).
Here’s an image I sourced from the Internet :
But there’s a catch. You can’t add an infinite amount of fuel because you need air to burn this fuel, lest the fuel remains unburnt and comes out of the exhaust and deposits on the tailpipe (The greasy deposits which you might have seen especially on tailpipes of obsolete 2-stroke two wheelers is this unburnt fuel).
Thus, to get more performance you need to burn more fuel and to burn more fuel you need to suck in a lot of air into that cylinder. One simple way of doing this is to have a larger capacity cylinder which will have a higher capacity to hold air and thus can burn more fuel giving a better performance.
However, be warned that a bigger engine also means that it will be less fuel efficient. Since it has to burn a definite amount of fuel to keep running it will consume more fuel even at low speeds when you don’t really need that performance.
Other ways are also prevalent to increase performance but this is the most primitive way of doing this.
However newer ways like turbocharging or increasing the compression ratio by using direct injection (D. I.) are far better methods because they do not compromise much on fuel efficiency.
Thus Bigger engine = Better engine doesn’t really hold true nowadays with improved technologies that has made smaller engines more powerful while at the same time being fuel efficient!
