Inboard vs. Outboard Motors: Everything You Need to Know

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Friday, July 23, 2021

A boat’s motor is a huge investment. It’s the heart of your vessel, so you want to avoid making the wrong choice. The tough part is that outboard and inboard motors are both valid choices and they’re both designed for different people.

If you want to make the right choice, then you’ll need to learn more about both motor types. In this piece, we’ll explain everything you need to know about an outboard and inboard motor, and we’ll help you pick which one is right for you.

What Is an Outboard Motor?

An outboard engine is an independent motor that mounts on the rear of your boat. Depending on the size and orientation that you opt for, there are two ways to operate these motors:

In one way, the motor is controlled through the helm. There is a throttle and steering wheel that operate the motor remotely.

In the second configuration, you’ll use a tiller that’s mounted directly on the motor. There may be a throttle to adjust the speed, or the motor might be a single speed. You’ll control the motor manually.

The second option is used mostly for smaller boats and smaller motors. Larger options are almost exclusively operated through the helm.

You can recognize an outboard motor quickly on a boat. You’ll see the large motor component attached to the rear of a boat, and a lower unit will go straight down that has the propeller attached to it.

Outboard motors are the only option that can be seen while sitting in the boat. All the components are mounted outside of the boat, hence the name.

What Is an Inboard Motor?

An inboard engine, on the other hand, has most of the components inside of the boat. The bottom of the boat near the center will house the motor. From the exterior of the boat, all you’ll see is an angled shaft with the propeller at the end.

From inside of the boat, you won’t see the motor at all. An inboard motor often has a separate rudder that steers the boat. 

A big difference between these two motor types is their mechanical properties. Inboard motors are close siblings to the engine you’ll find in a car. It has more horsepower, a higher torque, and can typically accelerate faster.

Since there is no physical access to the motor from within the boat, these are only operated from the helm.

The middle of the boat will be hollowed out and have a large box that the motor is housed in. That means troubleshooting and maintaining the motor is much harder. It requires a full disassembly before you can even see the inboard motor.

All About Inboard Motors

In this section, we’ll explain everything you need to know about inboard motors.

Pros

  • Really good fuel efficiency
  • Quieter operation
  • Smaller wake
  • Lasts over 6,000 hours
  • Better power and torque

Cons

  • Less space in the boat
  • Maintenance is more labor-intensive
  • Repairs are more complicated and expensive
  • Costs more upfront
  • Winterization is required annually 

Who Is an Inboard Motor Right For?

Inboard motors are the go-to for wakeboarders, water skiers, and people who want to tow multiple tubes. Why? They make a small wake and have a higher towing capacity.

They’re also preferred by people who often host guests on their boats. Since they’re much quieter, it’s easier to relax and have a conversation with others. 

Understanding the Fire Risk

Since inboard motors are positioned inside of boats, there is a fire risk. If you want to avoid this hazard, you can install a bilge blower.

This blower takes the hot and hazardous fumes and pumps them away from the engine compartment. It will blow them outside to minimize the risk.

All About Outboard Motors

Now, we’ll talk about outboard motors.

Pros

  • Much less expensive
  • Winterizing is easy
  • More portable
  • Maintenance is simple
  • Top speed is higher
  • More space inside the boat
  • More popular option

Cons

  • Not enough torque for heavy boats
  • Might need multiple motors

Who Is an Outboard Motor Right For?

Most people use an outboard motor for fishing, light commercial boats, or recreation. This is mostly because they’re cheaper, easy to maintain, and they don’t take up much space.

When you want to get the motor out of the way, you simply lift it out of the water.

It’s also the right option for people who want to go fast on the open water. Since they boast a higher top speed, you can have more fun.

The maneuverability, tighter turn radius, and quicker handling also allow you to unlock your inner speed demon.

If you hit shallow waters, it’s not a problem. The motor depth can be adjusted to get away from the bottom of the lake or river.

Comparing an Inboard and Outboard Motor

Let’s take a few minutes and look at direct comparisons of inboard and outboard motors. These variables might make or break your final decision.

The Cost

A big difference that’s worth talking about is the price difference between these two motors. If you look at options that have roughly the same specs, you’ll wind up paying much more for an inboard motor.

However, the same inboard motor will last much longer and require much less maintenance. If you look at the lifetime cost of these motors, you’ll probably spend more for an outboard.

The maintenance cost difference is even more dramatic if you pay a mechanic to do the repairs rather than do them yourself.

Ease of Docking and Low-Speed Maneuvers

An outboard motor requires speed and power to turn. You can’t really navigate unless you speed up the boat.

The independent rudder of an inboard motor allows you to maneuver at low speeds efficiently. This makes docking a lot easier.

Conclusion

At this point, you’re a motor expert. You just learned the difference between an inboard and outboard motor. If you have any questions, you can talk to our expert team at Michigan Wheel. Be sure to check out the rest of our site to learn more about your boat.