3 cylinder engine vs 4 cylinder engine creates a confusion for a car enthusiasts. This confusion even becomes more and more high after many companies introduced their 3 cylinder engines in the market. The Maruti Suzuki has replaced its older engine and introduced a new 3 cylinder engine in its Swift car. So here we will try to minimize the confusion and understand the differences between these two.
Which is better, a 3-cylinder or a 4-cylinder?
The automobile market is now shifting toward 3 cylinder engines, new and new 3 cylinder engines are being developed and coming in new cars, this is done to discourage the 4 cylinder engine in the market. But what is the reason that a 4 cylinder engine is being discouraged?
In today’s topic we will consider only In line 3 cylinder and Inline 4 cylinder engine because they are used in a car. Actually a 4 cylinder engine is considered more balanced and more stable, while 3 cylinder engine will be less balanced because the cylinders have to be on the same axis means on a straight horizontal line but in moving condition they all have to be stable.
3 Cylinder Engine–
In multicylinder engines internal combustion happens regularly. These cylinders have their firing orders in which they move up and down. No two cylinders moves together in a 3 cylinder set up. The movement happen one after another and according to these movement the blast happen in them. The firing order in a 3 cylinder engine is always uneven. So the cylinder creates an imbalance in the chamber. The movement of these cylinder is so fast and done in seconds.
Here comes a term RPM. RPM means revolution per minute means the number of revolution of a crank shaft per minute. So in a simple term we can say that the firing order in a 3 cylinder engine is highly uneven, that is why a 3 cylinder engine many a time remain imbalanced. This is one of a reason why the 3 cylinder engines have high NVH level.
4 Cylinder Engine–
A 4 cylinder engine has more balanced firing system. In this set up 4 cylinders moves evenly for example two cylinders at the middle moves together at the same time and blast happen in them at same time. The other two placed at the edges (the outer one) takes lower position when the middle one are at high position. After blast the middle two cylinders move down and at that time the cylinder at the edges move up and blast will happen in them. And similarly it happens at a regular interval. This is a more balanced condition in which a pair of cylinder balance the position of other two cylinders. The firing order of these is very even. Because of this balance is maintained a 4 four cylinder engine will experience less vibration. The movement happens in a fixed geometry and creating balance on the horizontal axis. Any engine always required this kind of balance to work efficiently. So a 4 cylinder engine is smoother as well.
But a 3 cylinder has such a geometry that it will be less balanced, because a 3 cylinder engine will have an uneven firing always. so this issue is bound to happen in a 3 cylinder engine,
So there are many steps followed to reduce noise of the engine, like engine balancing is done using extra weights are added at the crankshaft so that the vibration can be reduced and the stress on the crank shaft can be minimize. Although the balancing is required to be done in both of the engines, but even after that there is still a possibility of vibration and NVH. It is just that after that counterbalancing done a 3 cylinder engine will produce less harshness.
Also Read: Which engine is better 3 cylinder 1.0 TSI or 4 cylinder 1.5 TSI?
3 Cylinder vs 4 Cylinder pros and cons
A more discussion in understanding both engines will clear our doubts. We come to the next comparison now that what is a difference between a power and torque in both of these engines. The cylinder capacity in an engine is equal for every cylinder for example if 30Horse Power is produced by each cylinder then a 3 cylinder engine will produce 90hp power. In simple term, same size of Cylinder Bore(inner diameter of a cylinder) and same Stroke Length(length in which a piston moves) will create same power always. When a 4 cylinder engine with same cylinder bore and same stroke length reduced to 3 cylinder engine then it will produce less power. But at the same time it will consume less fuel and thus a 3 cylinder engine becomes more fuel efficient.
So a 3 cylinder engine will be having less torque and produce less power. But It will be fuel efficient and less heavy. It is easy to maintain and cheaper in price. The maintenance cost will be less for a 3 cylinder engine as compared to a 4 cylinder engine. Also the pollution from a 3 cylinder engine will also be less as compared to a 4 cylinder engine. 3 cylinder engine also a cost saving option for a company because of less engineering and smaller size. Almost 25% cost is saved in producing a 3 cylinder engine in a car. Also a 3 cylinder engine proved saving in taxation as per the norms.
Whereas a 4 cylinder engine will have more power and more torque, and it feels smoother. It will create less noise while driving. The power delivery is efficient and produces less vibration. The fuel economy of a same category 4 cylinder engine will be less, but it will be more refined and less noisy.
3 Cylinder Turbo Engine vs 4 Cylinder Engine Which is better
Whether a 3 cylinder or a 4 cylinder engine there will be those blast and those reaction occur for sure which we can not resist. Which simply means the pollution in a 3 cylinder engine will be less as compared to a 4 cylinder engine for sure. But a 3 cylinder engine will generate less power so how this will be suitable for a mid size car?
A solution to this is a use of TURBO. A turbo increase the power produced per cylinder which became at par to a 4 cylinder engine.
There should be a use case for a 3 cylinder turbo car before telling which is better. There are do’s and dont’s for a turbo charged car.
- A turbo charged engine remain in more stressed condition because we are fetching high power from a small engine.
- If a turbo charged engine is used for only city drive and we are using it for short trips regularly then it will create some issue not now but in long term for sure.
- Short trips are not able to make a temperature high enough to burn the carbon efficiently, because the requirement of a turbo charger for air intake and for fuel injection gets increased as compared to a Naturally Aspirated engine.
- Turbo require an optimum temperature to get activated. It actually gets kick in after 1500-1600 RPMs sometimes 2000 RPMs and in city traffic the engine hardly get over 2000 RPMs.
- The turbo works highly efficient when it attend high temperature. A turbo behaves good at higher RPMs specially on the highways, but at low RPMs there will be a turbo lag in power delivery for sure.
- Turbo charge engines also have to do more efforts in cold weather conditions. High revving a turbo car in specially a cold weather condition means your are trying to damage the engine heavily. High revving in a cold start will hurt any engine whether it is a turbo or NA so keep this in mind.
- Slow revving after a cold start should be followed. After an optimum temperature is reached like driving car for 9-10 kms then after that high revving should be done.
- Also a turbo engine have more parts so high maintenance and more expensive service will be there. Parts change can occur and that include expenses too.
- Short trips in an turbo engine will also damage the exhaust of a car because a low temperature is unable to burn the gases and carbon built up will happen.
- A turbo charged 3 cylinder engine if runs more on highway then the possibility of these issues are very less. Turbo engine should equally have highway running and thus we can enjoy its performance. Just keep in mind to drive slowly when you start the car for some initial kms.
Also Read: Petrol Engine vs Diesel Engine which Is Best
What are the disadvantages of a 3-cylinder engine?
Every car needs an efficient engine to fulfill the requirement as per the size of the car. The engine is everything a car depends on. It not only drive a car but help in running other things too like AC and electronics in a car. So it should be big enough that it can face heavy load, and do not run under heavy stressed condition. It is a limitation of a 3 cylinder engine. So for a small hatchback car a 3 cylinder engine will work very well because it will be having good power to weight ratio. They will provide a good mileage too. But for a mid size or a big car it is not suitable. A 3 cylinder engine makes more noise and has more vibration and more NVH level. It can not provide a ride smoother like a 4 cylinder engine.
3 Cylinder Engine vs 4 Cylinder Engine Mileage
A 3 cylinder engine will be having more mileage than a same type of a 4 cylinder engine. A 3 cylinder engine has more fuel economy and it comes with less parts. but the fuel efficiency depends on many factors like how a engine is optimized and how you drive the car. Hard push the accelerator will decrease the mileage in a 3 cylinder car also. Engine optimization and use of a car momentum will directly affect the mileage and pollution.
