The Engine Inside Your Car Is Either A SOHC Or DOHC. What’s The Difference?

Well, there are several differences when it comes to sohcs and dohcs, but we’ll focus on two of them:

The number of camshafts in each engine type with the way that Fuel is delivered to the cylinders. There are four cams in a SOHC engine and two in a DOHC; this means that more air can be drawn into an individual cylinder with each revolution of the crankshaft, which results in increased power for your vehicle.


Another difference between these engine types is how they deliver fuel-sohs use port injection while dohc uses direct injection.

In order to understand Sohc vs. Dohc, both types of engines in detail, read this blog post till the end!

SOHC Engines:

Sohc engines stand for a single overhead cam. They use port injection to deliver fuel, and this means that the intake manifold, under pressure from the camshaft, sends a small amount of pressurized air/fuel mixture into each cylinder on its stroke. This is then ignited by an individual spark plug in the same way as all other vehicles with sohc engines.

DOHC Engines:

DOHC engines stand for dual overhead cam. They use direct injection, which means the engine doesn’t rely on intake pressure to inject fuel-it directly sends a small amount of pressurized air/fuel mix into each cylinder during its stroke. This is then ignited by an individual spark plug in the same way as all other vehicles with DOHC engines.

What Makes Both The Engines Different: SOHC vs. DOHC:

The difference between SOHC and DOHC engines lies in the number of camshafts in the car engine. If there is only one camshaft, then it is SOHC whereas, in the case of two, it is DOHC.


SOHC: Single Overhead Camshaft

DOHC: Dual Overhead Camshafts.

DOHC engines have two intake and exhaust valves in each cylinder, while SOHC engines have one intake valve and one exhaust valve. This further tends to enhance the performance of the engine.

Well, the difference also lies in between some other aspects like performance and other aspects; let’s find out:

Which One Should I choose – Either DOHC or SOHC?

Now you know the difference between spark-ignition and compression-ignition engines, which one should you choose, and what are the edges and the drawbacks of these two types?

Performance Level

The first and foremost difference between the DOHC and SOHC engines lies in the level of the performance. Dual camshafts usually produce more horsepower, and they are often added to newer cars.

The possible reason for this could be DOHC engines typically rely on a 4-valve design instead of the one intake and one exhaust configuration seen in SOHC designs.

Older cars didn’t absolutely need a performance in the same way that newer vehicles do, and hence, they were fine with a single camshaft.

DOHC vs SOHC engines

The efficiency of the Fuel:

When it comes to fuel efficiency, how many valves a motor has can make a big difference. Dual camshaft engines often offer better efficiency than single camshaft motors. More performance can lead to lower fuel efficiency. Engines have more air when they’re running properly and performing better.

Repairing Price:

The major drawback of the DOHC engine is that you have many more valves, camshafts, and parts that can break down. The downside of DOHC engines is that they have more components than their OHV counterparts. In a single-cam engine, two pistons move up and down in time with each other inside the same cylinder, creating smooth driving while remaining economical.

In case you are wondering for are looking for a reliable engine that won’t get too hot, a SOHC design is probably the best choice for you.


Most modern cars now use a DOHC engine, which gives significantly smoother performance without misfires. This is because of the difference in efficiency and ease of control valve timing.

In case you consider smoothness as your priority, I recommend you choose DOHC.


Which One Should I OPT Either SOHC or DOHC?

Well! The answer to the above question depends on what you’re trying to find. The answer could be really subjective, depending upon your priority level. DOHC is known for delivering the best performance because you may get more horsepower with it. Whereas, if you tend to choose SOHC, then you are choosing reliability over any other factor. A SOHC engine is known for the lesser components offering better reliability standards.

What Is The Advantage Of DOHC?

If you are choosing a DOHC engine, then you definitely hold an edge over the more efficiency, and you’ll get more power output from the engine. Choosing a DOHC engine will further help you in reducing or keeping a better track of fuel consumption, all thanks to the efficiency.

Is SOHC An Honest Engine?

Well, a SOHC engine could be a good engine type, but the answer could be again very subjective, depending upon what are you really looking for? If you are in need of finding a reliable engine, then opting for SOHC could be a good engine for you. But if your need is to find out the engine offering you the better performance and good fuel consumption, then, instead of SOHC, you should go for DOHC, which makes maybe a more sensible choice.

How Do I Do Know If I Have Got DOHC Or SOHC?

The easiest and the simplest way is to test the specifications of your car repair, either manual or something similar. With this, you’ll be able to often also check the width of the engine cylinder. In case it’s wide, there are probably two camshafts denoting DOHC, and if you find out to be narrow to contain two camshafts, then it’s clear that you have got a SOHC engine.