Difference between 2 Stroke and 4 Stroke Engine

Difference between 2 Stroke and 4 Stroke Engine

Difference between 2 Stroke and 4 Stroke Engine ✅ The major difference in two-stroke powertrain and four-stroke motor lies in the timing of the firing ☝

The automotive these days comes with engines having higher fuel efficiency. To perform its function smoothly, n motor must complete is combustion process, which has four individual strokes of rod and piston inside the chamber. We all very well know that people has moved from old school 2-stoke powertrains to the four stroke drivetrains due to improved fuel efficiency and cleaner emission at a cost of power. The major difference in two-stroke powertrain and four-stroke motor lies in the timing of the firing. In order to understand it better, one first need to know what stroke is. They both have similarities yet they are different.


2 stroke and 4 stroke engine

It requires four processes of fuel burning with each process composed of one stroke. Given below are each individual stroke which is involved in the process.

  • Intake thump. The engine operation begins with intake stroke, where a piston is pulled towards the downward direction. This, as a result, allows fuel mixture and air to enter the chamber via intake valve. When the engine starts, the required power completes the first process is given by starter motor. A starter motor is a mechanical device connected to a flywheel. It is responsible for crankshaft spin and moves the individual cylinder.
  • Compression Stroke. Everything that comes down, comes up. This is what compression stroke believes in. This happens when the piston moves back up the cylinder. During the process, the intake valve is shut down, which squeezes the stored fuel mixture and air as the piston goes to the top of an internal combustion chamber.
  • The combustion stroke. This is a process where power is created. When the piston reaches the top of the cylinder, the gases which are compressed are ignited through spark plug. This, in turn, creates small explosion inside the chamber and forces piston to the downwards.
  • Exhaust thump. The exhaust thump completes the process, as the piston is again pushed upward through connecting rod, while exhaust valve opens up and releases the burnt gases.

Their comparison can be done on the given basis. The automotive thump is one revolution – means Revolution Per Minute is one complete engine cycle, our four-stroke per revolution. When a motor is idle at 1000 RPM, this means engine completes the process 1000 times per minute. They both advantages and disadvantages.

Difference between two stroke and four stroke engine

  • Though they both have the same duty to perform, still, they are different. The four-stroke motor allows every stroke to be happened individually, while two-stroke drivetrains requires all four-stroke to occur downward and upward stroke, giving it a two-stroke name.
  • The two-stroke engines do not require valves as both intake and exhaust are a part of combustion and compression of a piston, while this is not the case with four-stroke engines.
  • When it comes to two-stroke engines, it does not have a separate oil chamber, so it should be mixed in an optimum amount. A four-stroke engine, on the other hand, has a different place for oil and does not need mixing. Also, this is the easiest way to find the difference in two.
  • Also, one can identify the difference is through listening to their sound. The two-stroke motor is quite loud having a high-pitched buzz, whereas a four-stroke engine has soft humming sound comparatively. The two-stroke drivetrains are mostly found in lawnmowers and off-road performance vehicles while four strokes are powering our road vehicles.

2 stroke engine problems

The major issue with two-stroke powertrains is that it leads to a huge amount of carbon emission via exhaust. This happens as a result of mixing of fresh air mixture in exhaust gases. And for the same reasons, 2-stroke drivetrains generate a white smoke fume. This limited amount of fuel gets mixed with exhaust gases is ungovernable most of the times, hence, these motor types are less efficient. This is one of the major reasons why people have moved towards the much environment friendly four-stroke powertrains with monstrous and power machines. The change has helped people a lot when it comes to fuel efficiency at the same time being good for the environment as well.


These are pretty simple things to understand the difference in these two. They both vary in power and has the ability to perform differently. They can find in both petrol and diesel engines. Moreover, you can find the animations and videos online to understand it better. The change from two-stroke machines to four stroke machines has made various things simpler for people. To keep the vehicles, fuel efficient, engineers now days keep on working to bring new technologies to improve the functions and efficiency of the drivetrains. The rise of electric vehicles is the step towards the better future, as these vehicles has no ill effects for nature. The manufacturers across the globe has come up with some of the amazing products as Tesla is one such name.

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