boats come factory rigged with either a Mercury®
sterndrive engine, depending on the model.
Whichever you choose, both engine styles pair perfectly with our exclusive POWERGLIDE®
hull found on every model.
Which motor is right for you?
To start, you need to know the difference between the styles. A sterndrive, also known as an inboard/outboard or I/O, uses a marine-adapted automotive engine mounted inside the hull near the transom. It drives a mechanism that looks and operates similar to the lower unit and steering operation of an outboard. Because the drive unit projects from the stern, it's called a sterndrive. Since the sterndrive combines the components of an inboard-type engine with an outboard-type drive, it is also called an inboard/outboard or I/O.
An outboard is a specialized marine engine that uses components designed for
marine use only. It is attached to the boat's transom and turns to provide
On a sterndrive boat,
the inboard engine is enclosed entirely within the hull. This gives these boats a sleeker, cleaner look above the water line,
though interior storage capacity is reduced. This setup also allows unobstructed views to the rear, and the swim platform can
run the full width of the boat. With its heavier engine mounted right inside the transom, sterndrives can be somewhat slower
to get up on plane but are usually more fuel efficient. For watersports, sterndrives tend to produce bigger wakes and a
lot of low-end torque. Sterndrives also offer the familiarity and lower parts prices of an automotive-style engine but can
be a little harder to access inside the boat. Since the freshwater cooling system is also automotive based, the engine block
and manifolds must be drained before winter. In an effort to make this job easier, MerCruiser®
easy drain on many engines that helps get the water out.
An outboard has a higher power-to-weight ratio—it's lighter than a sterndrive
of similar performance capability. If you have a smaller tow vehicle,
you can "pack more power" with an outboard. Outboards offer quicker acceleration
and higher top speeds than similarly powered sterndrives, but fuel economy
may not be as good. Since the engine is mounted outside the boat on the transom,
interior room is unobstructed. However, there's
usually only room for smaller swim platforms on both sides of the engine. Since
all parts of an outboard system are designed for marine use and can be easily
flushed, they are generally more corrosion resistant than inboard engines,
and, therefore, more suited for saltwater use. And, because there is no closed
cooling system, an outboard can be used throughout the cold weather months
without the cost and inconvenience of winterizing or the danger of freezing.
Now that you know the basics, consult with your dealer to find what type of
power best suits your needs. Whichever direction you choose, you're in for
plenty of high-powered on-the-water fun!