Difference Between Inboard and Outboard Motors

Inboard and outboard motors are two common types of marine propulsion systems used in boats and watercraft. While both types of motors serve the same basic function of propelling a boat through water, they differ significantly in terms of design, location, and functionality.

Read this article to find out more about Inboard and Outboard Motors and how they are different from each other.

What are Inboard Motors?

An inboard motor is a type of marine propulsion system that is usually located near the centre of gravity within the hull of a boat. It is usually powered by a diesel or gasoline engine and is connected to the propeller through a shaft.

One of the most significant advantages of inboard motors is their power and dependability. Inboard motors can provide more power and speed than outboard motors because they are commonly larger and more powerful, making them a popular choice for larger boats and vessels. Inboard motors are also known for their reliability and longevity, with many thousands of hours of operation before requiring major maintenance or repairs.

Inboard motors have some disadvantages as well. They take up valuable space and can be more difficult to access for maintenance and repairs because they are located inside the boat. They also require a larger engine compartment, which reduces the available storage space on the boat.

Inboard motors tend to be operated by a throttle and a shift lever, which are similar to car controls. The throttle controls the engine's speed, while the shift lever engages forward, neutral, and reverse gears.

Inboard motors require routine maintenance such as oil changes, fuel filter replacements, and other normal duties. They are, however, easier to maintain than outboard motors, which require more frequent maintenance and are often harder to access for repairs.

What are Outboard Motors?

An outboard motor is a type of marine propulsion system that is located on a boat's transom, or back end. Outboard motors are normally powered by gasoline engines, but electric and propane outboards are also available. They are directly attached to the propeller of the boat and generate thrust and speed through the water.

Outboard motors' accessibility and ease of maintenance are two of their principal advantages. They are excellent for smaller boats and watercraft since they are mounted on the back of the boat and can be simply removed or tilted up when not in use. Outboard motors are also quite simple to maintain, with the owner capable of performing the majority of normal maintenance duties.

Outboard motors have some disadvantages as well. They may affect stability and manoeuvrability because they are mounted on the back of the boat, especially in rough waters or high winds. They are also less powerful in general than inboard engines and may struggle to produce enough thrust and speed for bigger boats.

Despite these limitations, outboard motors are a popular choice for smaller boats and watercraft due to their portability, ease of maintenance, and maneuverability. They are frequently used for fishing boats, pleasure boats, and other various types of recreational watercraft. Electric outboards have also gained popularity in recent years due to their environmental friendliness and quiet operation.

Difference between Inboard and Outboard Motors

The following table highlights the major differences between Inboard and Outboard Motors −


Inboard Motors

Outboard Motors


Inside the hull of the boat

Mounted on the transom (back) of the boat


It is known for its durability and longevity, being able to run for many thousands of hours.

It requires more maintenance but is relatively easy to maintain.


Inboards provide good maneuverability and stability, especially at high speeds.

Outboards can reduce stability and maneuverability, especially in choppy water or high winds.


Operated using a throttle and a shift lever, similar to the controls in a car.

Controlled using a tiller or a remote control system.


More difficult to access for maintenance and repairs.

Relatively easy to maintain, with most routine maintenance tasks able to be performed by the owner.


Ideal for larger boats and vessels

excellent choice for smaller boats and watercraft


In conclusion, the primary differences between inboard and outboard motors are their location, design, and functionality. Outboard motors are smaller, more portable, and located on the transom, whereas inboard motors are larger, more powerful, and located inside the boat. The decision between these two types of motors depends on the boat owner's specific requirements and preferences.

Updated on: 15-May-2023


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