What is Engine Capacity (cc):
The term “cc” stands for Cubic Centimeters or simply cm³ which is a metric unit to measure the Engine's Capacity or its volume. It is the unit of measuring volume of a cube having size 1cm X 1cm X 1cm. Engine Capacity is also known as ‘Engine Displacement’ which means the displacement of the piston inside the cylinder from Top Dead Centre (TDC) to the Bottom Dead Centre (BDC) in engine’s one complete cycle. The Engine Capacity is also measured in Liters corresponding to Cubic Centimeters.
If an engine has capacity of say 1000cc or 1000 Cubic Centimeters, then the capacity of that engine is 1 Liter.
For e.g. 1000cc = 1000 cm³ = 1 Liter = 1.0L
Similarly, 800cc = 800cm³ = 0.8 Liter = 0.8L
How to measure Engine capacity or Engine Volume:
To calculate the volume of an engine you can use the formula-
V = π/4 x (D)² x H x N
Where, V = Volume, D = Bore Diameter, H = Stroke Length, N = No. of Cylinders
The Engine Capacity is the combined capacity for all cylinders of the engine added together while it completes its one complete cycle. For example, if a four cylinder engine has capacity of 1000cc or 1.0L; that means all the four cylinders can together accommodate a maximum of 1000 cubic centimeters or 1.0L of volume of air in them. If the engine has only one cylinder, then that lone cylinder will accommodate all of the 1000cc or 1.0L of air inside it. By the way, the world's first automotive - the Mercedes-Benz MotorWagen featured a single-cylinder 1.0-litre engine (954cc to be precise) to power it.
How Engine Capacity affects its performance:
The engine capacity plays an important role in determining various engine outputs such as engine power, torque and mileage. The ‘Engine Capacity’ is the volume, in other words; the space available inside the cylinder to accommodate air-fuel mixture for burning. Consider, that it is just like a drum filled with water. Bigger the drum, more the water it can accumulate and guzzle. Similarly, greater is the volume of the engine sucks more air into the cylinder. As the volume of the air grows, the corresponding quantity of fuel supplied to the engine is also proportionately increased. As the amount of the fuel for burning increases, it results in higher power output. Hence, in simple words, the power output of an engine is directly proportional to the engine capacity in a conventional engine design.
Supplying more fuel to the engine, increases its power; and also its fuel consumption. As the volume of the cylinders increases, the power output also increases. But eventually, this reduces the mileage. Hence, in that context, the mileage of the car is inversely proportional to the engine capacity in a conventional design. The manufacturers keep upgrading the petrol engines and strike a balance between power and mileage to achieve both performance and efficiency.
How Engine Capacity affects mileage:
Typically the petrol car engines with best fuel mileage come in the zone of upto 1000cc. Those with capacities 1000cc to 1500cc have better mileage figures. Whereas, engines with capacities from 1500cc to 1800cc have moderate fuel average range. Those with capacities from 1800cc to 2500cc have lower fuel average range and the engines above 2500cc have the least mileage among all as shown in the chart below.
Almost identical set of rules apply to the smaller carburettor engines for bikes. Typically the bike engines with best fuel average come in the range of upto 110cc. Engines from 110cc to 150cc have better mileage figures whereas engines with capacities from 150cc to 200cc have moderate fuel average range. The engines with capacity from 200cc to 500cc have lower mileage and engines above 500cc have the least mileage among all, as shown in the chart below.
Hence, the engine capacity is a crucial factor for any automobile. You should decide it thoughtfully by analyzing the intended purpose or the end usage of the vehicle. So that you won’t be disappointed with the performance of the vehicle which you have selected.