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The Definitive Answer to Outboard vs. Sterndrive

By: Bill Jennings

An editorial discussing one of boating's most debated topics with Captain Bill Jennings

Which boat drive system is better-- an outboard motor or a motor with a sterndrive?? This debate has been around for too long. It is time to finally put this question to rest. I believe that when it comes to today’s general pleasure boating, we can now examine the pros and cons of each drive system and identify a winner.

While the first practical and commercially acceptable outboard motor was marketed by Ole Evinrude in 1907, it was not intended to compete with inboard powered boats. Their single cylinder only produced 1.5 horsepower. Over the next four decades, OB’s became larger-- but not by a lot. In order to offer greater horsepower without running gear under the boat, the idea of coupling an inboard engine to the bottom end of an outboard style drive was introduced in 1950 by Charlie Strang while he was working for Carl Kiekhaefer of Mercury Marine. Carl himself passed on the idea, but Charlie’s associate and friend, Jim Wynne left Mercury and kept working on the plans. When Charlie walked away from the project Wynne was free to market it elsewhere. He presented the details to Volvo and they introduced the first marine stern drive to the public in 1959. Kiekhaefer quickly acknowledged a missed opportunity and began to design one for Mercury in 1961. Outboard Marine Corporation followed suit. The sterndrive trend had begun.

Over time, we have seen lots of new propulsion ideas. Jet drives, Arneson drives and Foil drives introduced alternatives that some believed would revolutionize the industry. Instead, they have slotted into specialized applications and are now a small percentage of the overall drive market. New sterndrive manufacturers have entered the market, such as performance oriented Ilmor and Yanmar, while others have dropped out, such as OMC, but today if a pleasure boat is not an inboard, it is usually either an outboard, or a sterndrive.

But which is better? The answer has oscillated over the years.

As pleasure boats grew in size during the 70’s and 80’s, buyers wanted more power. Automotive engines with sterndrives became the obvious answer. Even the first Volvo stern drive was rated at 80 HP and with the growing automotive engine power, sterndrives became the “go-to” product. If you had the budget, you wanted a sterndrive. Outboards were not thought to be in the same league as the more powerful “inboard outboards."

But then, several developments gradually began to alter the preferential balance. When catalytic converters were mandated for auto engines and the EPA required changes to stern drive engines, the cost of sterndrive powered boats jumped. At the same time, outboard motor manufacturers began to introduce more powerful products and the sterndrive power advantage began to narrow. With the introduction of four stroke motors in outboards, the fuel saving benefits of sterndrives was further reduced. Then outboards lost their annoying high-pitched characteristic sound and dealers would leave them running at boat shows to demonstrate how quiet they had become.

Today, boat builders can easily locate an outboard motor tailored to their specific requirements, and with 350 cid V-8 outboards also in the offering horsepower is no longer a deal breaker. In the event that either boat weight or personal ego calls for more power, just keep adding OB’s until satisfied. To determine if outboard motors have truly graduated to become the preferred power choice, l prepared the following chart that looks at fifteen important factors that can differ between sterndrives and outboards and rate each one to a maximum score of 5.

Outboards win. By tallying up the feature and benefit scores between outboard motors and sterndrives, we appear to have a clear winner. Argument over-- for now.

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2 commentaires

Steve Noakes
Steve Noakes
24 sept. 2023

Nope. The debate will rage until fusion drives are invented.

I enjoy working on I/O. Generally, there is plenty of room on single engine units to do routine and even not so routine work. And removing the engine is simple with a basic gantry crane if needed.

Swapping motors for more power is simple. Adding more O/B for more power can be a world of hurt to the wallet and boat balance. Multiple outboards means multiple, less efficient fuel burners, multiple maintenance chores, multiple repair costs, multiple propeller strikes, less range with the same fuel capacity.

But lets face it. 99% of owners buy the boat and power as equipped and don't change power except for possible mods to the…


I have owned both and you are pretty accurate in your judgement. I would be interested in a cost comparison. A 100 hp outboard is valued close to the 10,000. Mark. Once you get up into the high HP outboards you can easily multiply that by 5-6. Compared to I/O I think I/O would be cheaper.

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