Inboard Vs Outboard: Which To Choose
One of the most important decisions you'll need to make when choosing the right motor for your boat is whether to go with an inboard or outboard motor. Both alternatives offer pros and disadvantages, and recognizing the differences will help you make an informed decision. In this article, we will look at the differences between inboard and outboard motors, highlighting their benefits and drawbacks to help you decide which is best for your boating needs.
What Is An Inboard Motor?
An inboard motor, also known as an inboard motor or sterndrive, is a propulsion system for boats that remains permanently inside the boat's hull. This type of motor is connected to a driveshaft, which controls the propeller's direction, thus steering the boat.
- Differentiating True Inboard from I/O
It is important to distinguish between a true inboard motor and an inboard/outboard (I/O) motor. A true inboard motor is completely situated inside the boat, while an I/O motor has components both inside and outside of the boat. True inboard motors are less common and are typically found in boats designed for skiing, as they generate less wake and provide smoother performance. On the other hand, I/O motors are more practical for family boats or boats that require greater versatility.
- True Inboard Configuration
In a boat with a true inboard motor, the motor is centrally positioned inside the boat, with a driveshaft connected to a propeller, which provides the boat with power. Unlike an outboard motor, the propeller itself does not steer the boat. Instead, a separate rudder is responsible for controlling the steering. In a true inboard configuration, the propeller remains fixed and cannot be adjusted vertically (up or down).
What Is An Outboard Motor
Outboard motors are boat propulsion systems that provide power through a motor mounted externally on the hull. They can be operated manually in smaller boats or connected to a steering and power system resembling that of a car in larger boats. One advantage of outboard motors is their ability to be fully removed from the boat for storage purposes or lifted to avoid contact with the water. This feature is beneficial for reducing erosion in saltwater or navigating shallow waters. Additionally, it aids in winterizing the boat. Steering in outboard motors is accomplished by moving the entire motor unit, which serves as a rudder, enabling left and right movement. Outboard motors are popular in boating due to their affordability, flexibility, increased seating capacity, and ease of maintenance. However, they tend to generate more noise and create larger wakes, which can be a drawback for water sports enthusiasts such as skiers.
Main Difference Between Inboard and Outboard Motor
In the case of family boats powered by inboard motors, they usually come equipped with a sterndrive, also known as an inboard/outboard or I/O powertrain. This configuration combines an automotive-type motor positioned inside the boat with a drive unit located on the stern, offering steering and trim capabilities. However, specialized water sports towboats feature an inboard motor that propels the boat from underneath, with steering control facilitated by a rudder.
Sterndrives are currently offered in a power range of 200 to 430 horsepower. It's worth noting that some smaller used runabouts might feature a discontinued 130-horsepower sterndrive. On the other hand, an outboard motor is a dedicated marine motor that attaches directly to the stern of the boat.
Outboard motors are available in a wide range, from small 2-horsepower kickers to powerful 600-horsepower options. For family boating purposes, the typical range of outboard motors falls between 90 and 300 horsepower. As outboard motors continue to increase in power, they are gaining popularity on larger cabin cruisers and day boats that were traditionally equipped with inboard motors. These boats may be configured with three or four outboard motors, collectively generating more power than the largest pair of sterndrive motors available. As a result, they offer performance that was once considered unimaginable.
When it comes to choosing a new boat, one important factor to consider is the type of motor. Depending on the boat model, you may have the option to customize the motor, while others may require you to follow the manufacturer's recommendation. For outboard motors, it's essential to allocate a separate budget for purchasing one or more motors in addition to the boat's cost. On the other hand, the cost of I/O and inboard motors are typically included in the total MSRP when buying a boat. To make an informed decision, it's recommended to consult with your boat dealer.