Outboard Motor vs Sterndrive: What is Best for Your Boat and Why?

Outboard and sterndrive engines are the two most popular drive systems on the water. When choosing between both, remember it’s less about horsepower and more about how you want to use your boat.

Outboards are like the multitools of marine engines—lighter, easier to maintain, and great for shallow waters. Sterndrives, on the other hand, offer a smoother ride better fuel efficiency, and leave you with a clean, open swim platform. But which setup is right for you?

In this post, we'll present a complete comparison between the two most popularly used boat engines to help you pick the one that fits your boating style.

What Are Outboard Motors?

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Outboard engines are attached high on the outside of the boat (transom). The motor is accessible, visible, and can tilted out of the water. The outboard motor has a small gearbox with a single propeller configuration. These engines are easy to steer, but they are not as powerful as inboard motors, you can always attach multiple outboard motors to your boat for extra power.

What Are Sterndrive Engines?

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Sterndrive motor is a combination of inboard and outboard motors. The engine type has an inboard engine, typically a marinized automotive engine, which powers the boat via a gearbox similar to outboard motors. The sterndrive engine is in the back of the boat under the transom. The main drive unit is tucked beneath the swim deck. Sterndrive units typically have single or twin-propeller configurations and can be found in a number of brands.

History of Outboard Motor and Sterndrive Engine

In the 70s and 80s, boats started getting bigger, which led to higher performance demands. The sterndrive engine was the only option; they are automotive engines offering unmatched power. There wasn’t an outboard motor that came close.

Then, in the same time period, the US government imposed strict catalytic converter policies to meet environmental standards. It increased the prices of the sterndrive engine, and as a result, boaters started preferring outboards. The 2-stoke outboard motors were loud and inefficient, and it was harder to get a motor bigger than 200HP. The evolution in technology led to efficient four-stroke engines. They are quieter, fuel-efficient, and powerful enough for bigger boats. Moreover, you can even find 500HP outboard motors.

Outboard Motor vs Sterndrive - Side by Side Comparison

Features	Outboard Motor	Sterndrive Engine
Power & Performance	Higher power-to-weight ratio, faster acceleration	Lower top speed, more stable in rough water
Weight	Lighter	Heavier
Fuel Economy	3-4MPG at Cruising Speed for 200HP motor	3-6 MPG at cruising speed for a 200HP motor
RPM Efficiency	Faster at the same RPM	Slower at the same RPM
Maintenance	Easy access, DIY-friendly, lower labor cost	Harder access, higher labor cost
Sound	Traditionally louder, but new 4-stroke engines are quieter	Quieter because they are mounted under the boat’s body
Winterization	Simple DIY process	Complex requires professional
Space & Aesthetics	More cockpit storage, smaller swim platform	Full swim platform, clean look, and less cockpit space
Tilt Function	Tilt function for easy maintenance, shallow water navigation, corrosion resistance	Sterndrive engine cannot be tilted because of its placement

1. Power & Performance

When it comes to the performance of the outboard motor vs. sterndrive, it is essential to consider the power-to-weight ratio. Historically, outboard motors were no match to the sterndrive, but the amount of horsepower you can pack in the modern outboard engine is a game changer. Another deciding factor is the weight.

A 200HP outboard engine from Yamaha and Suzuki weighs around 525 lbs, while a 200HP sterndrive engine from Mercruiser weighs 756 lbs. It is over 200lbs more than outboards.

So, the lighter motor performs better and is easy to handle. On the contrary, sterndrive engines are comparatively slower but offer stable and sturdier rides on rough waters.

2. Fuel Economy

Despite being lighter, outboard motors are less fuel-efficient.

In our testing, the Yamaha 200HP outboard engine delivered 3-4 miles per gallon at cruising speed. While Mercruiser sterndrive engine under the same condition delivered 3-6 miles per gallon at cruising speed.

One interesting thing to notice in the test was RPMs. Outboard engines have higher RPM ratings than sterndrive engines. At 3000RPM, an outboard engine was 6mph faster than sterndrive engines.

So, if we evaluate everything, there’s not a huge difference. But over the course, outboard engines are marginally less fuel efficient.

3. Maintenance

It is important to consider the maintenance cost of outboard engines and sterndrive. We cannot predict your engine's specific repairs other than the routine oil and filter changes and necessary repairs that might be needed over time.

However, keep in mind sterndrive engines are placed under the boat’s body. They are not easy to access, so the labor cost is higher for routine maintenance and repairs. On the contrary, outboard engines are mounted outside the body and can be tilted for easy access. They are much more DIY-friendly; you can conduct most maintenance in or out of the water. Outboard engine parts are also comparatively cheaper, and many reliable sellers offer used outboard parts for budget boaters.

Learn: Used vs New Outboard Parts – How to Decide?

4. Sound

Historically, sterndrive engines were much less noisy due to their placement. The outboard engines are placed outside, and old outboards are two-stroke, which is very loud and irritating. The newer four-stroke outboards are very quiet, especially at lower RPMs.

You should consider noise level, especially if you are hosting family and friends fishing trips on your new boat. In our testing, modern-day outboards and sterndrive engines are in the same category.

5. Cost Comparison

Outboards and sterndrive motors are completely different designs, so generally, you would think prices will be significantly different. Both engine types have fairly similar prices, but outboards have comparatively less upfront cost.

6. Winterization

Winterization is important for boat engines if you live in cold areas where the temperature falls to freezing.

Sterndrive engines are marinized automotive engines, making them more sensitive to the cold. So, to avoid any risk of freezing, you will need an extensive winterization process. As the engine is hard to reach and has a complicated operation, the winterization is usually done by qualified marine mechanics. Moreover, the sterndrive engine must avoid freezing temperatures. So, to prevent extensive damage, the boat should be out of water early. Early winterization and extensive de-winterization processes also reduce the boating season.

The Outboard engine's winterization process is much simpler. You can even DIY, which means you will be up and running in no time in the spring. Moreover, you can tilt the engine up instead of taking the boat out of the water to avoid freezing. Tilting also drains the water, allowing you to extend the boating season.

7. Space & Aesthetics

Sterndrive engines under the boat’s body provide a complete swim platform on the back, providing easy access to the water. The boat’s interior is uninterrupted, providing essential space for hosting family and friends' fishing trips.

On the contrary, if you choose an outboard motor, you will lose space on the back but gain some cockpit space for storage.

The aesthetics is an individual choice. Many like to have the engine completely out of view, so Sterndrive engines are the right choice. While others prefer the look of an outboard engine on the back of the boat. The aesthetic choice is all about personal preference.

8. Tilt

Only outboard motors can be tilted because sterndrive motors are mounted underneath the boat and out of sight.

Tilt is a handy feature of the outboard motor:

1. You can move the engine up and tow it out of water.
2. It allows you to navigate shallow water easily.
3. Tilting it up reduces exposure to marine growth and corrosion from salt water.
4. By tilting the outboard motor, you can drain all the water out of the engine, protecting it from damage and the risk of an unexpected overnight freeze.
5. The engine is also easy to maintain and repair while keeping the boat inside the water.

With a sterndrive engine, you cannot enjoy the above-mentioned feature as the engine isn’t accessible.

Outboard Motor vs Sterndrive: Which One Should Power Your Next Boat?

Over the past few years, the outboards have come a long way. Making the choice between sterndrive and outboards much more competitive. However, in the end, we recommend evaluating your needs and engine features before making a final decision.

The outboard motor is lighter and has faster acceleration and higher top speed. Moreover, it has much more storage and tilt ability to access shallow water. Meanwhile, Sterndrive has a better fuel economy and a wide-open transom. If you want to perform some water sports activities like skiing and surfing, sterndrive is the ideal choice.

FAQs

Are outboards better for saltwater?

Outboard motors are ideal for saltwater. They can be tilted up and out of the water. The anode material is also different depending on salt and fresh water usage. Freshwater outboards have magnesium anodes, while aluminum and zinc are used for saltwater usage.

Are sterndrive engines reliable?

With proper maintenance, winterization, and storage, sterndrive engines can be very reliable. Most issues arise when you neglect servicing and improperly store them.

Ready to upgrade or maintain your engine? Check out our Outboard Motors and Sterndrive Engine Parts for top-quality options and expert support!

Posted by Brian Whiteside