SOHC vs DOHC: What’s the Difference and Which One You Should Choose?


The abbreviation of SOHC is Single Overhead Cam. It also can be understood as there’s as it were one camshaft within the head.  

The perplexity between SOHC and DOHC may turn your head. But, sometimes recently moving forward and clearing your questions, it ought to be clear that these motor types may have a few pros and cons that produce them different from one another. 

Both SOHC and DOHC manage to gather the limelight for their superior performance when it comes to engine efficiency. But to help you choose better, we have listed out certain factors that will help you make a better choice when SOHC vs. DOHC is in question. 


What Is SOHC Engine?  

The abbreviation of SOHC is Single Overhead Cam. It also can be understand as there’s as it were one camshaft within the head. Inline motors will have one camshaft. Level motor and V-engine will have two camshafts, one per barrel bank.  

What Is DOHC Engine?  

The abbreviation of DOHC is Double Overhead Cam or Twofold Overhead cam. It can also be understand as each header has two camshafts. Subsequently, an inline motor will contain 2 camshafts because it has as it were one header. Level motor and V-engine will contain 4 camshafts as they have two headers. The DOHC motors ordinarily come in 4 valves. One camshaft for the admissions valves and the other for the deplete valves. 

DOHC Engine

SOHC or DOHC which one is the better choice 

Each type has its own characteristics, which make them unique and different from each other. Let us learn more about the difference between SOHC and DOHC to help you make a better choice.  

1. Operation  

SOHC is a simple single camshaft with adjustable gas inlet and outlet, while DOHC is a double camshaft with dedicated gas inlet and outlet settings. Compared with SOHC, this further means that DOHC has dual intake and exhaust valves. Therefore, this makes the engine temperature lower and has an equal work distribution, which in turn brings a smooth, noise-free and effective ride experience. 

2. Valve timing  

It is known that the valve can start the operation of the engine. Also, the timing of the intake and exhaust of gas depends on the shape and angle of the camshaft. When it is necessary to optimize the breathing process, variable valve timing is required to increase the maximum horsepower. As we all know, due to the availability of a single camshaft, SOHC design has less control over valve timing than DOHC, which makes DOHC more flexible in adjustment. 

3. Fuel efficiency 

As mentioned earlier, each valve of DOHC is set to double. This in turn means that more power will be consumed due to the enhanced control of the valve. The greater the power, the greater is the fuel consumption. Therefore, when comparing the fuel efficiency of SOHC and DOHC, the fuel efficiency of SOHC is higher. However, it should be known that only the skill of the driver and the design of the engine can make the DOHC engine reflect fuel efficiency. You can look for maintenance tips to help you learn how to better manage engine efficiency. 

Fuel efficiency

4. Price  

When you think about the question of “what is SOHC”, as long as you know that it has a rotating cylindrical rod, you can adjust the suction and discharge of gas. This requires tolerance on DOHC, and DOHC has unique settings for gas in and out. Compared with SOHC, DOHC has doubled the number of valves, which makes its design simpler and therefore cheaper than similar products.  


After studying the viewpoints of the two engine types, you must have a clearer understanding of SOHC and DOHC. Similarly, it should be known that both SOHC and DOHC have their advantages and disadvantages, but when choosing a better option in consideration of market trends, it is undoubtedly DOHC. 

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