Car engine types: Different types of automotive engines
There are several types of engines used in automobiles. The car engine types are generally described based on two factors: the fuel type and engine layout/number of cylinders (cylinder configuration. One of the most common types of engines is petrol and diesel engines. But that’s a generic way to describe a car engine.
Apart from diesel vs. petrol, several other factors differentiate one engine from another. The following sections will explain different types of engines used in cars based on the factors mentioned above.
How do car engines work?
When you turn on the ignition key, the engine comes to life. But have you ever wondered how an engine works? Modern-day engines generate power via internal combustion or controlled explosions. It is achieved by igniting the air-fuel mixture inside the engine's cylinders. This process is called the combustion cycle, and the process repeats thousands of times per minute to propel the car.
A combustion cycle has four strokes (steps). Hence, modern-day engines are also called four-stroke engines. The four strokes include intake, compression, combustion and exhaust. Below are the detailed explanations of each stroke.
Intake: In this stroke, the piston moves down, and the intake valve opens and releases the air-fuel mixture inside the combustion chamber. The valve opens and closes with the help of a camshaft. The piston moves up/down with the help of a crankshaft.
Compression: As the name suggests, the piston moves up and compresses the air-fuel mixture inside the combustion chamber in this stroke.
Combustion (Power): The spark plug produces a spark during this stroke and ignites the compressed hot air-fuel mixture. It causes a small explosion, and the energy generated by it pushes the piston down. This store provides the power to propel the vehicles. Hence, it’s also called a power stroke.
Exhaust: As soon as the piston moves down, the exhaust valve opens. And when the piston moves up, it pushes out the gases generated by the explosion via the exhaust valve. The cycle repeats thousands of times per minute to power the vehicle.
Note: The above working mechanism is of a petrol engine. The diesel engine also works on the same principle, but fuel injectors replace the spark plug to ignite the hot air.
Types of automobile engines in India
Here are the types of auto engines used in cars in India.
1. Naturally aspirated engine
It is an internal combustion engine. It’s also called a normally aspirated engine or NA.
In this type of engine, air intake depends on atmospheric pressure.
It does not use forced induction of air into the intake manifold.
It produces less power than forced air induction engines (turbocharged/supercharged).
It is simple in construction and more reliable than forced air induction engines.
2. Turbocharged engine
It is an internal combustion engine with forced air induction.
An additional component called a turbocharger is used for forced air induction.
A turbocharger comprises a shaft with a turbine at one end and an air compressor at the other end. The components are housed in a snail-shaped covering with an inlet port.
The waste exhaust gases enter at high pressure via the inlet port.
The exhaust gases pass through the turbine, and in turn, it spins the compressor.
The air compressor sucks in more air that is compressed and passes through the air outlet port.
The air is fed into the cylinders via an intercooler that cools the air before it reaches the cylinders.
Since the air pressure is higher than atmospheric pressure, the engine produces more power.
3. CRDi engine
It is a type of diesel engine known as a Common Rail Direct Injection (CRDi) engine.
CRDi is a fuel injection technology used in modern diesel engines.
It comprises a single common rail (line) to supply fuel to all the fuel injectors.
CRDi engines can maintain a constant fuel injection pressure due to the presence of a common rail.
Due to the constant pressure, the fuel spray is very fine and is evenly distributed. It helps in enhanced efficiency and power.
ECU (Electronic Control Unit) regulates the fuel injection pressure depending on the speed and load on the engine.
4. MPFI engine
It is a type of petrol engine which is also known as Multi-Point Fuel Injection engine.
MPFI is a fuel injection technology used in petrol engines. It is similar to CRDi, which is used in diesel engines.
The MPFI system makes use of fuel injectors to deliver the exact amount of fuel to each cylinder.
Due to the precise fuel delivery system, MPFI enhances fuel efficiency.
MPFI also increases the engine power output.
MPFI engines are refined, and they also start effortlessly even in cold weather conditions.
MPFI engines produce fewer carbon emissions due to the precise fuel delivery.
Common car engine layouts
As mentioned earlier, auto engines are also classified based on cylinder layouts. Different car manufacturers use different layouts to accommodate the engine under the bonnet or to extract more power. Below are some of the common car engine layouts used by car manufacturers.
1. Straight
In a straight layout, the cylinders are arranged in a straight line parallel to the car (front to back).
The straight engine layout allows for more cylinders. The more the cylinder, the more the engine displacement. Hence, more power output.
The straight engine layout is mainly used in powerful sedan cars from the stable of BMW, Mercedes-Benz, etc.
2. Inline
The cylinders are arranged side-by-side across the engine bay (perpendicular to the car).
The inline layout allows for a compact arrangement of engine components. Hence inline engines are compact in dimensions.
Inline engines are mainly used in hatchbacks and small cars.
3. V
The name ‘V’ refers to the shape of arrangement of cylinders when viewed from the front.
In this layout, the cylinders are mounted at an angle of 60-degrees on either side. So, the rows of cylinders face outside to form a V-shape.
The pistons of all the cylinders are connected by a single crankshaft at the base.
The V layout can accommodate a lot of cylinders. Hence, it is mainly seen on high-end supercars.
4. Flat
In this engine layout, the cylinders are arranged horizontally. The two rows of cylinders face outwards.
Flat engines are uncommon. They are known to offer a low centre of gravity due to the arrangement of cylinders.
Hence, flat engines aid in driving dynamics and impressive handling.
Porsche is one of the largest manufacturers of flat cylinder engines. The iconic Porsche 911 sports car makes use of a flat-six (6 cylinder) engine.
Car engine cylinder configurations
The car engine cylinder configuration is nothing but the number of cylinders in an engine. There are several types of configurations which are listed below.
Twin-cylinder engine: Nowadays, this type of cylinder configuration is not used in cars. You can find twin-cylinder engine two-wheelers. The reason it’s not used in cars is the low power output.
Three-cylinder engine: It is a configuration that is generally used in small cars. However, with the introduction of turbochargers, three-cylinder engines are also used in large hatchbacks. One of the drawbacks of this engine is the lack of refinement due to the odd number of cylinders.
Four-cylinder engine: It is one of the most common configurations found in modern cars. Four-cylinder engines generally feature an inline layout in almost all small and large vehicles. Unlike three-cylinder engines, these engines are refined and can produce more power with the introduction of turbochargers.
Five-cylinder engine: It is a very rare configuration, and it has become almost obsolete. A five-cylinder also suffers from vibrations due to the odd number of cylinders. Manufacturers like Volvo, Audi, etc., adopted the five-cylinder configuration.
Six-cylinder engine: One can find this configuration in high-end or sports cars. Generally, these engines feature a straight or V engine layout. With the advent of turbochargers, six-cylinder engines have become more powerful.
Eight/Ten/Twelve (or more) cylinder engine: Eight (or more) cylinder engines are only used in supercars. They are generally in V layout and are called V8, V10 or V12 engines. These engines produce massive power due to their large capacity.
Also, read: How to check engine oil level in a car?
Most powerful car engines in India
The engine is the source of power to propel the vehicle forward—the more powerful the engine, the higher the car's performance. Although India is known for its fuel-efficient engines, the new-age buyers look for more power for an engaging drive. Hence, car manufacturers have also come up with powerful car engines in India. Below is the list of some of the powerful engines in India.
1. Kryotec 2-litre turbocharged diesel engine
The Tata Harries SUV comes with a powerful 2-litre Kryotec turbo-diesel engine. As an SUV, the engine needs to produce more torque, and Tata Motors has done a great job tuning this diesel engine. Below are the power figures of this reliable oil burner.